DIY ADC Adapter

It’s been a while since I added a blog entry, but this is worth it. This time I am building a DVI to ADC adapter so I can connect an old Apple Cinema Display to a PC.

The Backstory:
The PR department at the college I work for was going through some old stuff. They came across some Mac equipment they no longer wanted and asked my office, the Help Desk, to dispose of it properly. What came back were some Apple video cables and one 20″ Apple Cinema Display. It wasn’t the aluminum version, but the older white one that looked like an easel. Of course, this display couldn’t be connected to any regular computer because it used an ADC connector. Apple specially engineered the ADC connector so that power, video, and USB were carried along a single cable. While this was great for reducing the amount of cabling you had, it also meant you had to have either a PowerMac with a compatible video card or a DVI to ADC adapter. That originally cost an $130. Oh, don’t forget your computer had to have a DVI.

The Idea:
If you fast forward to today you can buy a DVI to ADC adapter for $75 from That would be the quick solution for connecting the monitor to a computer, but I have an idea: why not build my own? The ADC standard is basically the same as DVI with extra wires for power and USB ports. The pinout on the connectors between DVI and ADC are a little different, but shouldn’t be too hard to over come.

The Research:
Searching the Internet revealed some good information. Most of what I found discussed building a VGA to ADC adapter for the older CRT Apple monitors, but nobody had instructions for building the DVI version for the LCD monitor. Regardless most people recommended looking at the Apple development library to see the ADC pinout and spec (1). I also found a few more important articles from Apple. The Apple DVI to ADC Adapter: Compatibility Table (2) has a note that says the monitor must be plugged up to USB to have brightness, power, and sleep functions. Another page, the Apple Cinema Display Tech Specs, (3) let me know the power requirements. From all of the research I did, here was a table showing what pins would need to be connected.

Pin 1 25 V Supply
Pin 2 25 V Supply
Pin 3
Pin 4 Pin 17 TMDS data 0−
Pin 5 Pin 18 TMDS data 0+
Pin 6 Pin 19 TMDS data 0/5 shield
Pin 7
Pin 8
Pin 9 Pin 7 DDC data
Pin 10 Pin 8 Analog vertical sync
Pin 11 Pin 15 25 V Return
Pin 12 25 V Return
Pin 13
Pin 14 Pin 9 TMDS data 1−
Pin 15 Pin 10 TMDS data 1+
Pin 16 Pin 11 TMDS data 1/3 shield
Pin 17
Pin 18
Pin 19 Pin 6 DDC clock
Pin 20 Pin 22 TMDS clock shield
Pin 21 USB Data+
Pin 22 USB Data-
Pin 23 USB Return
Pin 24 Pin 1 TMDS data 2−
Pin 25 Pin 2 TMDS data 2+
Pin 26 Pin 3 TMDS data 2/4 shield
Pin 27
Pin 28
Pin 29 Pin 23 TMDS clock+
Pin 30 Pin 24 TMDS clock−
C5 C5 Ground

Included in the pile of cables that came back with the monitor I found an ADC to DVI cable. This cable was made by Belkin and was designed so you could connect a regular DVI equipped monitor to a PowerMac with an ADC connector on the video card. It did the same thing I wanted, just in the opposite direction. Still, the ADC to DVI cable allowed me do a signal test between contacts and confirm the my chart was correct.

The Parts:
To build the adapter here is what I purchased.
1x ADC connector, $3.00 (4)
1x DVI connector, $4.84 (5)
1x USB connector, $1.12 (6)
1x Power connector, $0.63 (7)
1x Protoboard, $16.85 (8)
1x 90W 24V PSU, $8.76 (9)

Total: $35.20

Other things I needed were a solder iron with very fine tip, solder, solder flux, a steady hand, and a good bit of luck.

Note: I couldn’t use a regular protoboard from Radioshack because of the hole spacing. The ADC and DVI connectors are based on the SMD (surface mount device) standard so the pins are spaced at 1.9mm. A standard hobby board has holes spaced at 2.58mm or 0.01″. The board listed above is the only one I found to be punched at 2mm and have solder pads.

The Build:
Putting everything together was tedious, but fairly straightforward. I started by installing all of the connectors onto the protoboard. This took some work because the pints were spaced at 1.9mm and the holes at 2.0mm. After a little but of wiggling everything lined up.

Now for the hard part. I had to carefully solder a wire to each of the desired pins. This was made especially difficult because of the some wires cover pins I needed access later. The solution was to solder wires on the pins closest to the middle of the board and then work my way out, attaching the wires on to the other connector when necessary.

The beginning:

The result:

With the hard part of the project the next step was to protect it from damage using a case. What project would be complete without an Altoids case. Lucky enough I had an Altoids tin sitting around for a future project. Lucky me. Using a Dremel and cutoff wheel I cut holes in the side of the case for the ADC, DVI, USB, and power connectors.

Here you can see how everything looks installed.

The Payoff:
After checking all of the input/outputs based on the chart above the only thing left was to plug in the cables. I was honestly surprised not to find any smoke rolling from the case. What’s more surprising was to see my computer detect the monitor and a picture actually show up. The screen was bright, responsive, and the colors looked good. I also connected the monitor to my PowerMac and was able to control the brightness of the backlight; something not possible from Windows 7 64-bit.

And there you have it. One working home made DVI to ADC adapter. Not bad for an amateur electronics geek.

I case your were wondering about the loose wires and red toolbox, the PSU I ordered hadn’t arrived yet so I had to use my DIY project PSU to power the monitor. It really wasn’t designed to output enough amps for the monitor, but worked for testing.


Here is a wiring diagram of the adapter. I just wish it was as easy to physically run the wires as it was in the schematic.

  • Rich

    Hi, I;ve got a G5 PowerMac that has ADC and DVI display output. My 23″ Apple Cinema Display that is connected to the ADC on my G5. I recently acquired another 22″ Apple Cinema Display with ADC connector. Can I use your method so I can connect the 22″ monitor to the DVI output on the G5?
    Where do you connect the USB and Power on the ADC/DVI pin?? It doesn;t show in your diagram??

    • Hi Rich,

      Yes. You can use this adapter to connect your 22″ monitor to your PowerMac G5 through DVI. I have a PowerMac G4 with an ATi 9800Pro, which only had VGA and DVI. I had no trouble connecting the monitor to it.

      For the USB connection There are no pins on the DVI connector for USB. Instead what I did was buy a female USB connector and run wires from the ADC pins 21, 22, and 23 to it. That’s what the small, square white connector is. From the USB connector I run a regular printer cable to the computer and that gives me the USB access. If you look at the pinout of USB you will notice there is a 4th connection for +5 volts. It appears there is no connection for this through the ADC connector. Instead +5 volts is provided to the USB ports on the monitor by an internal power regulator.

      For power I did basically the same thing. I bought a female barrel power connector, which is the small black connector in the photos. I ran a wire from pins 1&2 to the positive side of it and wires from pins 11&12 to the negative side.

      I guess I need to make a block diagram showing all of the wiring. That would help clear up some confusion.

  • Rich

    Thanks for your fast reply.. Is there anyway you could built/sell ones of those gadgets? I don’t really have time to make one let alone find parts for it. And yes a block diagram showing all the wirings would certainly help for those wanting to built one.
    BTW, I also came across this blog……
    Thought you might want to check it out if you hadn’t already seen it..


    • I doubt I would build another one. the soldering work is so tedious. I spent three evenings securing all of the connections. Everything I purchased to build the adapter is in the post. What’s sad is when I built this project just over a month ago you could buy the official adapter from’s resellers for $75. Now they are no longer available.

      Regarding the other blog. That’s certainly another way to do it. I didn’t want to go that extreme and hack the monitor. If I would have screwed something up then the monitor may had been unusable. Thinking along those lines though, there used to be a product called the DIVator, which was a third party adapters. It was basically an ADC receptical on one end, a short run of cable, and DVI/USB/power connector on the other.

    • George Work

      Hi Rich,

      Please refer to post #50. I found a pristine (probably 2008) 23″ Cinema Display in the trash. But, the entire cable has been cut off about 4″ from the back of the monitor. I need information about connecting wires contained in the monitor cable to the powe supply, DVI, and, if necessary, the USB interfaces. I have accessed an inexpensive, appropriate 24 V PS and DVI cable on eBay (about 20 bucks total).

      Can you assist with this project? Tony recommened I contact you.


  • Rich

    Thanks again for your reply… Well I guess I would have to build one myself but the problem is I live in Hong Kong and finding the Female ADC would be impossible. Even though this might be the place of electronic things, some parts are not available…Any chance you could send me the all the parts and I can pay you with Money Order? You could send me the items once you’ve receive the MO and have cleared in your bank. What do you think? It would really help me a lot..


  • Thanks for that. My $10 monitor is now functional, and what I thought were scratches on the screen were in fact just smears of dirt. (OK, so it was $10 plus 2 hours of careful splicing of the the ADC cable with a cut-off DVI cable).

    This one’s going straight to the simpit! 🙂


  • BTW, my total investment was $10 for the monitor and $2.50 for the donor DVI cable.

    (I didn’t want to invest serious money in it, because until I could get some digital signals into it there was no guarantee that it would actually work).


    • Hi BTH,

      I’m sorry for not approving your comments earlier. WordPress never emailed me letting me know you had posted. That’s cool that you got your monitor working by splicing a DVI cable on the end. Can I ask how you powered it?

      • I’m currently powering it the old-fashioned way: a 24V 2A iron-core transformer with a full-wave bridge rectifier. There’s no filter caps or voltage regulator, but it doesn’t seem to mind so far. (I’ve also ordered a cheap “universal laptop AC adaptor” from eBay, but it’s taking its time arriving).

        I didn’t bother with the USB hub, because each of the computers in my simpit already has 8 USB ports.

        Here’s a photo gallery of my simpit – I had to separate the monitor from the back half of its case to attach it to the bracketry:


  • liumpen

    Nice work!
    Can you please send your block diagram showing all the wirings.
    I planning also to try it

    • Hi liumpen,

      The update I made at the end of the post has a wiring diagram I created in MultiSim. It may not be a 100% representation of the physical pinout of the connectors, but it’s the best I could do with visualizing how each pin is wired together.

      If potentially making your monitor unusable isn’t a worry, then you might look into what BTH did and splice a DVI cable onto the end of the monitor cable. That would require cutting the ADC connector off and finding a way to connect power.

  • jmb2112

    Nice job! I’m thinking of doing this with a 20″ cinema display by cutting off the adc connector and soldering wires together. I would also use a cut up DVI cable, cut up usb cable and connect a jack for an ac adapter to plug into.

    I believe you can clean up the wiring by just connecting all the ground, shield and return lines together. I checked my ADC cable and pins 3,6,11,12,16,20,26 are connected together and to the connector shell (multimeter shows continuity). On the DVI connector of my video card, pins 3,11,15,19,22 are connected together and to the connector shell. So, I’m guessing you can take these 5 or 6 wires on each side and just connect them together.

    • Hi Jim,

      Your right, all of the grounds can be wired together for convenience. I didn’t talk about it in the article, but I have all of the ground connections running to a corner of the board where they are bridged. Soldering the wires to the board at the ADC/DVI connectors was so tedious that any simplification I could do was welcomed.


      • “Tedious” is the price we pay for “cheap”! 🙂


  • Shane

    I wanted to thank you for this info. because of your wiring diagram, i was able to make my own adapter. Unfortunately, i have big hands, and needed to make the board a little larger, and couldn’t use the altoids tin (which really made this cool). So i picked up a cheap plastic welder and made my own enclosure. I’m working on artwork for a PCB, and when i get it done, i’ll share it with you.

    • HI Shane,

      That’s really really cool that you were able to build your own adapter. I can’t wait to see what you’ve come up with.

      • Luke

        Hi Shane, Please send me pict link of your workingcheap plastic welder.

  • Hi – great work!
    I did this mod a few days ago, and I wondered how this “Hotplug” feature would work. Finally I found the solution in the DVI documentation. For EDID-capable monitors (which is the case for the ADC), the Hotplug pin (16) should be connected to the +5V pin (14) via a 1kOhm resistor. This causes the graphics card to read the monitor’s resolution data from the EDID.
    Regards, JL7

    • That’s interesting to discover. I wondered what “hotplug” was for and if I would even need it. If hotplug is wired up, how does it affect the use of the monitor? During the build I decided to get the monitor working with as few wires as possible and got lucky. On both OS X and Windows 7 the monitor is recognized as an Apple Cinema Display along with all the usable screen resolutions. I assume this is because of the data being sent over the DCC.

      • I did not try to plug my monitor without that resistor, so I don’t know the corresponding behaviour.
        The DVI specification says that the hotplug pin tells the OS that the monitor contains EDID information and it can be read over the DDC. But it is OS dependent how the reaction will be. Maybe OS X or Windows 7 do not care about the hotplug pin and read the EDID data anyway, regardless of the hotplug pin. Maybe other OS do care about the hotplug pin?
        However, the DVI specification explicitely proposes this pull-up resistor solution as an easy implementation for the hotplug feature. That’s why I did it.

  • Alex_mp

    That project is great, I am implementing a solution as we speak and I was wondering if you connected the TMDS Data 5+/- pins, I can’t see them in the diagram. I am making the PCB ( which I will later share) and I was wondering if it would hurt to connect them…any advise?

    • Hi Alex_mp,

      From what I understand TMDS 3, 4, and 5 are used for dual DVI link monitors (30″ and above). Since the largest ADC monitor Apple made was 23″ i left those connections out of the projector for simplicities sake. The fewer solder joints I had to do the better. You could trace those contacts for your PCB, but they will never be utilized. Your probably better off tracing the VGA connections in case anyone wants to use the old CRT studio displays. C1-C4 would have to be added, but that shouldn’t be too difficult. Also, take note of JeanLuc7’s comment. While I didn’t do anything with DVI-pin 16 (hot plug) it appears a 1KOhm resistor needs to be connected between it and +5V.

      Too bad you didn’t tell me last wee you were designing a PCB. I just spent the weekend building a new adapter. The joints in my original adapter were beginning to break do to the relativity large gauge wire used and the fact they just sat on top of the PCB. For this new adapter I took the Ben Heck approach to wiring: IDE ribbon wire. The smaller gauge was much easier to work with and solder. Don’t worry, I still used a thicker gauge wire for power.

      • Alex_mp

        HI Tony!

        Thank you for the fast reply. You’ve just read my mind about the other TMDS pins. However, since I am doing the PCB, the extra wiring will not be much of a problem, but I appreciate the concern. About the 1K resistor, I already put it in after reading JeanLuc7’s comment.
        I am sorry to hear about your extra work soldering the ribbon cable, I have done that myself in other projects and I know your pain.
        So, about the VGA, it sounds easy to do…I am looking for a VGA footprint in my libraries right now.
        I’ll keep you posted! Thanks again.

        • Alex_mp

          Last, thought…Can I connect the softpower pin (13) to a potentiometer or something like that to control the brightness?

          • That I’m not sure of. I never really figured out what that pin was for or what to do with it. From my testing, the brightness and power buttons are controlled by the operating system and not the monitor itself. That is why the USB connection is required (see link 2 in the post).

            I think the monitor is in a constant state of standby because as soon as the OS detects it and sends a signal it will wake up regardless of whether or not you ever press the power soft button. On Windows the buttons do nothing when you press them unless you have a program like WinADC installed. On OSX the power button becomes an extension of the computer’s power button. When connected to my PowerMac G4 the button will put the system to sleep since that is what is set in Energy Saver.

  • Alex_mp

    Hi Tony,

    Just to thank you for your help and to let you know that I have uploaded the PCB design to a website where you can order it and use it if you’d like. I used a couple of recycled molex connectors (DVI and ADC female) from an old Apple G4 video card that I had around. I changed the USB B type that you used for a smaller mini AB female that apparently works fine and left the power input to an unspecified connector (two padstacks marked in the silkscreen).
    I also decided to connect all the pins, since I was not doing the heavy lifting, and put the 1k resistor in the hot plug detect and another 1k resistor (it can be jumped) to the LED pin. The only pins not connected are the C1-C4 and the soft power; although the VGA output sounds appealing, it wasn’t going to be used in my case….so, maybe in the version 2.0.
    If everything works I may be putting everything up with pics and more details…of course linking your blog.


    • I’m working on a similar solution, although I’m going to add the wiring for the VGA. Did you ever find a layout for the ADC connector? I’m using the datasheet for the DVI connector available at Mouser and linked above, and have used HD-15 female connectors before along with barrel jacks and USB-B. Today I designed a part in EAGLE, did a measure-and-test-print with the ADC from Surplus Supply (it has the same 0.075″ grid as the DVI with more pins and the same C1-C5 configuration too although all in subtly different places) and need to work out a few errors and will probably drill 0.1mm big on the mounting holes for some more wiggle-room.

      I’m designing it in EAGLE as KiCAD is still a thorn in my side on the Mac (I get a bunch of missing library errors, and still don’t fully understand the flow). The target is a board that is Altoids-ready and OSHW. I’m probably going to use Advanced Circuits ’cause I have soft spot for American companies (plus their specs and capabilities are better) then sell boards or completed units somewhere online.

      • Hi Jason,

        From hand building my own adapter I can say the ping layout for ADC is the same as DVI, just with two more rows for pins. I’ve never used EAGLE before, but if you can create a custom DVI layout and add the extra pins then everything should be okay. Using the Indestructibles article linked to above, here is a table of everything that must be wired together so VGA will work.

        ADC DVI Use
        Pin 3 Pins 14 & 16 5V+ & Hot Plug
        Pin 9 Pin 7 DCC Data
        Pin 10 Pin 8 Analog Vertical Sync
        Pin 19 Pin 6 DCC Clock
        Pin C1 Pin C3 Analog Blue
        Pin C2 Pin C2 Analog Green
        Pin C3 Pin C4 Analog Horizontal Sync
        Pin C4 Pin C1 Analog Red
        Pin C5 Pin C5 Analog Ground
      • I noticed on Alex’s Instructable that he made a “version 1.1” board, but in the blurry image of the layers on BatchPCB’s site, it looks like it says 1.0. I had sent a message on Instructables but didn’t hear back.

        Anyway, I finished up my ADC-DVI-VGA version that fits in an Altoids tin and sent it to BatchPCB last week. I got a quote from Advanced Circuits, but the prices work out so it’s about $400 to start at any quantity (e.g. 10 is about $40 each) down to $10/each for 100. I couldn’t justify it in case (a) there was a bug, and (b) whether I could sell more than 5 to make up for it. Once I confirm the design works okay, I’ll open it up for sale.

        • I did have a bug in the board but it’s inconsequential (I missed one ground connection on the DVI, but there are other grounds). However, I did manage to bring up the monitor. Peculiarly the USB hub works but the brightness controls never appear in the displays settings (on Mac OSX 10.6.8 on a Mid-2010 Mini). I didn’t check if it appears in System Profiler. But today I’m going to see if I can buy a bigger one from the local Mac guy.

          Anyway, I’ll update the design then publish it on BatchPCB. Look for updates here and at .

          • With the monitor working and USB hub detected try putting the computer to sleep and wake it back up. Or reboot. I noticed the brightness controls don’t appear in the system preferences until afterwards.

  • Alex_mp

    Sorry for the late reply. I just posted this a few min ago.

    • Very Nice.

      • Alex_mp

        Hey Tony, one the PCBs is yours for free if you want, just send me your address to

  • raj

    hi tony,

    Can make this one more for me? I can pay you the cost.
    its needed for one of our study project this semester.


  • Gabriel

    Hey, I’ve tried to convert my 23″ apple display to DVI and have run into a problem.

    I connected all the wires as per this PDF file ( and I used a “universal laptop power supply” at 24v to power the monitor.

    When I first turned it on the power light came on and nothing else, no image on the monitor.

    Unfortunately, I was impatient to test it out and I connected it before I had even insulated the wires.

    One loose orange wire from the ADC connector (pin 3, the LED) touched the +24v from the power supply. I heard a slight pop from the monitor, and now the power light only shines when I touch it, and goes out right after.

    Did I just destroy my monitor? I’m hoping someone can point me in the right direction 🙁


    • Hi Gabriel,

      I’m not sure what could have happened to your monitor. It sounds like maybe a capacitor popped, but without cracking the case open there is no way to know. I think the soft buttons connect to the USB interface and not the panel circuitry so the problem may just be a miss wiring of the ADC-DVI pins. When connected to a PowerMac through ADC the power light/button of the monitor becomes more of an extension of the power button of the desktop. You can literally turn the Mac on from a cold start using the monitor. Apple’s documentation for the official ADC-DVI adapter states that to get button functionality as well as brightness control of the monitor you must connect the USB cable to the computer. Under both Windows and OS X I’ve had the monitor turn on without having to press the power light or needing the USB cable plugged in. Windows will not detect the monitor automatically unless you to either go into the display settings of Windows and click the detect button or boot/reboot the system with the Apple monitor connected (XP: Control Panel > Display > Advanced tab > Detect button) (Win7: Right-click on desktop > Screen Resolution > Detect button). Once detected the monitor will instantly power on. The same is pretty much true for OS X when I tested it under 10.5.

      If you are still having issues then I would double check the wiring of your adapter using a circuit tester or multimeter. Make sure there are not any crossed or loose wires. I had a lot of problems out of my first adapter because one or more of the wires were loose. Double check with the table and wiring diagram provided above. The only way I can think of testing your monitor to see if it still works would be to connect it to a PowerMac with ADC compatible video card. Practically every PowerMac from the early G4s up though the mid to late G5s will have a card that works.

      The interesting thing about my Apple monitor is the power light has no bearing on panels current status while using the adapter. Pressing the power light just makes the button illuminate and stay on until I unplug the power adapter. Under OS X the situation is the same unless you plug in the USB cable and restart the system. This has more to do with USB driver support as you can see from one of the other articles I wrote.

  • Oh joy. After a few days of tinkering around, I made a circuit board to connect VGA to the ADC. Alas, it doesn’t work.

    One thing that is disconcerting is that if I plug the USB connection into the Mac, it does not show up at all in System Profiler (even though the USB power goes through.) The power to the monitor seems to work as I can touch the power “button” and it lights up yellow (presumably stand-by mode); brightly while it’s being touched and dimmer when not.

    I wonder if it could be my monitor is broken or if ADC monitors just won’t do VGA. I also tried hooking the VGA to a PC (a.k.a. a full-time virus checker that occasionally permits using software … grr …) but that didn’t work either. I could log in by VNC but the display showed up as generic and adjusting options (e.g. 60Hz. 1024×768) would not make the ADC monitor come on.

    I guess it’s back to the drawing board. It’s too bad there’s no way to tell if my monitor works. I think I might just give it to the Mac place in town that sells some old systems that have a built-in ADC port. Thank goodness I didn’t drop $1,000 on several hundred custom boards, although those would have DVI, VGA, and ADC ports and might have worked.

    • Is the apple monitor you have CRT or LCD? The clear plastic, LCD displays only accept a DVI signal and will not work with VGA. The older CRT Apple displays used VGA and I think maybe the first generation LCD displays with translucent blue casings. Don’t quote me on that.

      • OK. I suspect you may be right. This is a clear/white/gray-case LCD so it might be DVI only. I may try bringing the adapter to the Mac guy in town to see if he has an older blue LCD monitor — at least the adapter would be useful to someone.

        Is it possible for you to confirm the USB behavior? If you connect only the 24V power and USB but not the DVI, does the USB monitor come up on the System Profiler? If it does, I suspect my monitor might be broken.

        • Just checked: Yes, when only the USB cable and 24V power is connected to the monitor System Profiler shows a new hub and attached to the hub is “Studio Display”.

          • I checked my solder joints and tried again and got so far as to get a hub to appear, but no display adapter. We shall see.

  • Sean

    Hello and thank you for such a thorough tutorial! I, too, have the 23″ Apple Cinema Display (clear plastic w/easel-type stand) but no G4 or ADC equipped
    video card, so this blog was right up my alley. I decided to build my own, as well, since the cheapest Apple Adapter has skyrocketed to a ridiculous $225!
    Some places are even higher than that! I also decided to go with the pre-made board via – and I just got it yesterday. It’s a very tiny little
    board, 2″ x 1 9/16″ – but it appears to be based around your original parts list, so all of the other parts I’ve ordered should plug right in to it.
    Cost was a bit of a surprise, though. $7.11 for the board itself; plus an additional $15.50 for shipping and handling. But, if you consider the fact that it
    is ready to go, without having to wire each pin-to-pin, I’m thinking that it really is a bargain. Plus, I’m not the greatest at soldering, so (hopefully) this will
    make life much easier. I should also point out that it took a little more than 3 weeks for it to get to me. This is because of the way BatchPCB must handle
    their orders. I thought they had a bunch in stock already, and could just pull from those. Turns out, they must hold on to the order and when they have
    several (not necessarily the same board as my order, though) ready to submit, then they’re off to the manufacturer. Hence the name “BatchPCB”. I hope
    this info will be useful, since there seems to be quite a few of your readers who are determined to right yet another Apple “proprietary” wrong.
    I do, however, have a question for you, Tony: Is it critical that a 90w power supply be used? Would a 70w suffice? The one at Amazon is certainly a
    great price ($14 today) but the reviews all say it’s absolutely not worth it. There is a similar universal PS for about the same price, only it’s 70w.

    Again, thanks so much for your blog – and especially your time!

    • Hi Sean,

      Thank you for the kind words and information about BatchPCB. According to Apple’s own technical specifications a 70W adapter is big enough to power a 23″ cinema delay. The important thing to remember is you need to a power supply that can output at least 24 volts.

  • Sean

    -> I initially typed the following in Microsoft Office, so I hope it copies over to the “comments“ section; I’m thinking it probably won’t…

    When I read your blog for the first time, I thought to myself: “No problem – I can do this! And save upwards of $200 in the process. Cha-ching!”
    So, after giving it some more thought – and reading through your blog at least a dozen more times – reality began to slowly creep in….. I mean, I really suck at the most important part: soldering. The only soldering tools I had consisted of: a Weller woodburner; and a Weller “pistol” type; you know, the tip looks
    like a wishbone? It has a light that goes on when you pull the trigger and dual-temperatures: Red Hot and
    “Don’t-even-think-about-pulling-the-trigger-this-far-while-near-electronics” Hot!

    Fortunately, my local Fry’s Electronics had a Weller WLC-100 Soldering Station on sale for about $44. Amazon had one, too; free shipping – but it was only a dollar cheaper, so I went to Fry’s. Oh, and for five more bucks I picked up an ST-7 Conical tip (for very fine work!). By the time I got back home the anxiety over this whole soldering thing – was gone! Using the right tools, almost anything is possible. Well, to a degree, anyway. But I digress.

    Okay, meanwhile, after reading that someone (Alex_mp I believe) was in the process of designing a professional PCB just for this very project, well I was completely blown away. I just did not figure it could be done without ordering at least 500 units. But, hey, this is the 21st century, right? (I saw an ad a few months ago, offering a plasma cutter that will fit in the corner of someone’s garage! There’s no end of custom
    stuff you can make with something like that.) So I am absolutely buying the board from BatchPCB! At
    that point, I was so excited about – at last – the prospect of seeing the Apple Display come to life!

    I remember reading the MaximumPC review, for Apple’s new 23” Cinema HD Display.
    In a world still dominated by the CRT, Apple had again pushed the envelope with
    this LCD masterpiece. I believe they said it was a visual nirvana. The likes of
    which, at their press time anyway, were unattainable to even the most devout
    IBM-compatible Buddhist!

    That was almost 10 years ago, though. A lot has changed. I can’t remember how much they were,
    in 2003, but I know it was an outrageous amount of money. So, check it out; like you Tony, the one I
    have is also from a school. My roommate was able to get one that was damaged and slated for the
    garbage. The extent of the damage, is why I was sure that – from an operational standpoint – it would
    work great.

    For some reason, whenever Apple hits the proverbial ball out of the park, (and they certainly did so, with
    this display) some unknown force steps in and makes certain that said ball will find its way to the nearest Apple store and shatter one of their signature “Walls of Glass”! In fairness, I suppose one could argue that they do learn from their mistake(s); perhaps. Although, I’ll wager more than a few iPhone owners are scratching their heads, wondering why the latest model got a revamped non-backwards-compatible
    charging system. I mean no ill will toward Apple people. Obviously, I’m in the IBM-compatible camp,
    otherwise I wouldn’t have needed to seek out an adapter solution in the first place. Anyway, I seem
    to be drifting again. Sorry.

    The easel! The incredibly lame design that holds the display upright. Well, the one I have is broken.
    At first I thought: “Is that all?” But then, when it arrived here – I could see that it actually was going to
    be more of a problem than I initially thought. So, I tried several (also lame, I know) of the best
    epoxy’s available, but none of them worked. It’s the crappy pot-metal that attaches the foot (easel)
    to the back of the display via 3 tiny little screws. I was, however, able to overcome the problem,
    by using various materials found around the home! Alas, I cannot take the credit, since it’s really the intellectual property of Rube Goldberg! If only I had somewhere to upload some photos. That way, you
    and your readers could marvel at a rare and “original” Rube Goldberg design!

    Okay, I know it’s too late to make a long story short. So I won’t try. I’m using the Apple display right now! And while it may not be a LaCie – it is every bit as breathtaking as I imagined, when I first read that review!

    Also, in case anyone is interested, I thought I would list what I had to purchase and the cost. Because
    I opted to use the pre-made PCB, I wasn’t able to use all of the parts that you did. I also should have
    known better than to assume the USB and PS connectors would plug right in to the PCB I used!
    (I’m chalking it up to the fact that I was so over-enthusiastic about the overall project!) Additionally,
    I have a few concerns I’m hoping someone might be able to help with. Almost every time I reboot,
    I get a great deal of visual “noise” – similar to that which you’d see in the Matrix movies. It does this
    right up to the point when the log-in screen is displayed. From then on – until I reboot again – it’s
    beautiful! Also, I downloaded WinACD and installed it; but when I try and use the Virtual Control Panel,
    under the “ Controls” tab in my display properties, it simply says: “None present”.

    As I had mentioned about the USB and PS connectors, above, I should also point out that I had to
    improvise, slightly. I’m using an old (but in excellent condition) USB cable that came from a mouse.
    I just stuck each wire, into its respective hole and soldered them in place. I plug the other end, into
    one of the USB slots at the back of the computer. For the two PS wires, I used a couple 24 AWG
    wires, about three inches each, and ran them from the PCB to a connector, similar to yours,
    that I attached to the project box. I’m guessing that the USB wires are the answer. The end that
    goes to the PCB has a fifth wire for ID; I did not attach it, even though there is a spot for it
    on the board. I did, however, attach the Vdd wire, as well as both of the Data wires and the Ground.
    Could that be the noise problem? When I plug in to the USB on my computer, Windows tells me that
    the device is not recognized. I suppose I’m going to need to order a USB panel-mount connector
    that will fit my PCB.

    Not sure if this last concern is important, or not. But in case Alex_mp still checks your blog, I’ll go
    ahead and ask. There’s two spots on the PCB, marked: R1 and R2. I used a 1k ohm 1/8th Watt
    resistor in the R1 spot. I’m wondering if 1/8th Watt is okay?

    Finally, for all of you who contributed suggestions and comments to Tonys blog; Thanks so much!
    None of this would have been possible – at least in my case, without all of the input!

    Above all – were it not for you, Tony – I would never have undertaken this project to begin with!
    I sincerely thank you, for taking the time to write this blog and for being so gracious with everyone.

    Here’s my Parts List:

    QTY Description Part # Cost (USD) Purchased From

    1 WELLER Soldering Station (w/ ST3 Tip) WLC100 $ 43.93 Frys Electronics
    1 BatchPCB Member Design: DVI to ADC 2 [1.45”x1.96”] 72231 7.11 *
    *Additional Shipping & Handling cost, for PCB above: ($5.50 + $10.) 15.50
    1 DVI-I Connector (Right Angle, Chassis) CPC-11-0201H29 2.50
    1 DVI-I 34 Pin Apple Video Jack CPC-DV3R035N11 3.00
    1 DC Power Connector PCB 2.1mm 163-7620E-E 0.63
    1 USB Connector Type B Recept. R / A w/Solder Tabs 538-67068-9001 1.12
    1 WELLER ST 7 Iron-Plated Copper Conical Tip ST 7 5.00 Frys Electronics
    1 Universal Power Supply Switchable 15v – 24v DC (Can’t find invoice) 19.95
    Total: $ 98.74

    ***NOTE: Most will not need the two WELLER items; bringing the total down to: $ 49.81
    which, in my opinion, beats the heck out of $200 plus for the Apple Brand
    adapter! Oh, I almost forgot; BatchPCB sent me two boards for the price of
    one. But, with the S&H they charge, I really shouldn’t consider it a “freebie”.

    So; that appears to be it. If you read this far – I salute you! Thanks again, Tony!

  • Sean

    Hi Tony. I’m not trying to be a pest, but while the display works fine, I’m really confused over the USB connection. Since I received 2 PCB’s from BatchPCB, I built another one.
    But when I use a VO meter, the 3 USB lines seem to be shorted; ie: the meter beeps when I touch the D+ to the GND or to the D-. It also does it on the new board.
    The display is still fine, but Win XP does not recognize the USB when I plug it in. Even though it shouldn’t, it really drives me nuts.

    • Hi Sean,

      Sorry for not getting back to you on the last post. I really need to get back on adding content to the blog.

      I’m not sure what could be causing the short. I never purchased a PCB that Alex_mp designed so I cannot know how well it worked. In the Instructable article he wrote I see where he talked about the mistake on the traces in version 1.0 of the board. The 24V+ power line ran over GND and D- of the USB traces. I’m assuming that much power running through the USB system is bad. Glad he caught it before plugging it up. I haven’t seen the layout of the 1.1 board to know how he remedied the problem.

      In regard to the questions in the last comment: 1. The noise could be caused by a monitor/video card/system incompatibility. The 23″ ACD may not be designed to handle the resolution+refresh rate the computer is sending during initial boot up. Not until the video card drivers load does the everything figure out the correct settings. I don’t think the connected VDD or disconnected ID wires are the problem. The USB hub in the monitor is powered from its own built-in regulator (I assume) so the VDD connection on the PCB doesn’t go anywhere. The ID wire is designed to allow USB devices to switch between host and slave modes. It has no effect on the hub in the monitor or your computer so doesn’t trace anywhere either.
      Regarding the comment “Windows tells me that the device is not recognized”: was that for both the built-in hub and monitor control? They show up as individual devices. Plugging something into the hub (like a flash drive) will tell you if the wiring on the original PCB you had worked.

      If I had a way to see a 1.1 PCB through high res photos or something I could maybe help if this issue, but not sure how much.

      Side story:
      Back in the PPC days, the same video card for PowerMacs was more expensive than their PC counterparts even though the PCB’s looked identical. A few ingenious users found out that many times the only difference between the cards was the EPROM chip used to store the low level device code was 128Kb on the PPC cards vs 64Kb on the PC. If you soldered a larger EPROM on the PC card and flashed the PPC ROM, you suddenly found yourself with a much cheaper video card for your PowerMac. What more, the same people figured out how to hack the PPC ROMs and cut some of them down to 64Kb and fit on the PC EPROM. In the process the card was unusable until the OS X booted up and loaded the video drivers. It was a really cool time back in the mid 2000s. A few people had managed to find a NVIDA 7800 AGP edition card that could accept the Mac ROM and get the card to work in PowerMac G4s.

  • Sean

    Yo know, I did see that part in his instructable, but I assumed that the board I was buying would be the updated version. It wasn’t. However, I did receive two PCB’s
    in my order, which was actually a blessing in disguise! Last night, I took one of the boards and decided to try a fix. In his design, he has the “DATA-” and the “GND”
    traces, running through the power supply “GND” that goes to pin 11 on the ADC. Well, after a crash course in USB signaling and wiring, along with the way the Apple
    display is wired – I figured that these two traces are not meant to share a common ground. At least the “DATA-” isn’t. So, I physically cut the two traces, before and
    after the main ground trace; then, I simply used two jumper wires to run them from pin-to-pin. Much like the way you did yours. Guess what? It WORKS!!!!! The USB
    ports on the back of the display work now; the Apple Control panel (via WinACD) works as it is supposed to and I am absolutely thrilled!!

    I think in fixing the first bug, Alex didn’t realize that the second one was going to surface. I totally see the logic in what he did. I’m no designer, not by a long shot!
    But it seems to make sense, particularly on such a small footprint, that you would want to consolidate as many traces as you could. So, anything that was a “RETURN”,
    “-“, or “GND” would probably be joined at some point. I’m sure I would have done the same thing. USB, I found, is designed with simplicity in mind, as well as many
    thousands of plug/unplugs by the end user. Unfortunately it is not “simple”. Durable, perhaps, but not simple. Since your board was wired pin-to-pin exclusively, I
    knew that it had to work. Yours did!

    I’ll tell you, though, after soldering just the two jumper wires, I don’t think I could have done it the way you did. I just don’t have the patience. I got ahold of a camera
    and I’m going to take some close-up shots of both the boards I have, so you can see what I did.

    Speaking of the video cards, for the Mac; does your Mac have the card that uses both the AGP and the PCI slot at the same time? When they came out with that, about
    the closest thing the PC had, was the dual Voodoo cards that used two PCI slots. SLI. Only SLI stood for something else, in those days – I forget what, though. Apple really
    was way ahead of its time; the graphics they provide have always been second to none. But you’re right, they have always been too expensive – at least for me. Plus,
    they don’t play nice. You know what I mean? They think that they know what’s good for their customers; and if we don’t agree, too bad – so sad. But, what are ya gonna do.

    Okay, I’ve written way to much again. I will let you know when I have the pics ready. In the next few days, or so. Thanks a million, Tony, for your time and your ear! You’re
    the best!


    • That’s good to hear you got USB to work. You are correct, Data- does not equal GND. Data- is supposed to act equal and opposite to Data+. Having it pulled to ground would cause problems.

      My original adapter actually started to fail a few months after completion. The wire I used was too thick so the solder joints were weak. When I rebuilt the adapter I took the Ben Heck approach and used ATA Ribbon cable to connect all of the data lines. With the cable split into strips of 3 wires I could keep things better organized. It was still very tedious to solder together since I was dealing with wires the thickness of a few hairs. I also caved and installed it into a RadioShack project box.

      I never had two video cards in my PowerMac, but according to the web it would work. Right now the system is running the original NVIDIA Geforce 2 MX card. I have an ATi Radeon 9800 Pro, but since the box has been converted to a storage/media server I took it out. The ATi card draws 40 watts of power over the NVIDIA.

  • George Work

    I found a very nice Apple 23″ Cinema Display Monitor in the trash this past weekend. Problem is, the entire cable was cut 4″ from the back of the monitor. I can access an appropriate, inexpensive power supply and DVI-D cable on eBay, but I need assistance connecting the wires.

    Where can I get help with this? I’m sure it will be a project, but worth my effort if I can get assistance.


    • Sounds like you will need to find out what each color coded wire is. If Apple followed the DVI standard then it should be easy to figure out. You will have to identify the USB and power lines and break them out to appropriate connectors. I would suggest looking at comment #3 in the above comments. The referenced modder may be able to answer more detailed questions since they hacked the monitor’s cable.

  • What a great site with just the info I need, as my 23″ went dark.

    I assume it’s the power supply (this would be Apple’s A1006), but just to be sure, I measured pins 1 and 11 and got zero volts where, according to the digram I should have gotten 24v.

    Before I go and order a replacement unit that can’t be returned am I correct that if there’s nothing between these two pins the PSU is dead?


    • That is probably a good guess. The only “gotcha” would be if the PSU is switched so it would provide power unless the monitor was attached. Unfortunately, I do not have an official adapter to test with. If you plug the monitor up, and the power button doesn’t light up when you press it, I would assume the adapter is bad. A $120 adapter is cheaper to test then a new 23″ monitor.

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  • Eric

    Hi could i pay you to make one of these for me because i need one yet I dont have the money to buy an actual one of the time/resources to make it myself?

  • chuck

    i was having problems getting the monitor to pc recognized the monitor as a tv and i set up dual screens but i am unsure how to turn on the monitor.. the power “button” on the monitor isnt fuctioning. Has anyone else run into this bug?

  • Eladb

    Great hack.
    I’d like to connect an Apple 23″ Cinema display to my laptop but I only have a VGA output. Is this also possible and has anyone had any success at this one?
    BTW what is the purpose of the USB connections on the ADC connector?

    • Sadly no. The Cinema Displays do not support VGA input, only DVI. Getting a converter that takes a VGA signal and turns it into a DVI-D signal would be expensive and you could probably buy a new monitor for the price. If your laptop had HDMI output then you could easily go from HDMI > DVI > ADC since all three use the same signalling. The physical connections are the only difference.

      The USB connection on the ADC adapter serves two purposes:
      1. Controlling the monitor from the desktop. There are no physical buttons on the display for adjusting the brightness or turning it on/off. Those buttons are just controls that go back to the computer, which then sends commands back to the display to act accordingly. I learned that on my PowerMac G4, the power button on the monitor replicates the power button on the tower. If the system is completely shut down then I can press the power button on the monitor to start it up.
      2. Provides USB pass-through for the hub built into the back of the monitor. The acrylic Cinema Displays have USB 1.1 hubs and the aluminum models have USB 2.0.

  • @ Tony …. is there now a working pcb layout or diagram that I can base a pcb on ?gerber / excellon format or other?

    • Not that I am aware of. You might be able to contact alex_mp directly and get a copy of PCB board he designed. Version 1.0 has an error that requires cutting a trace and soldering some wires to the board. He said version 1.1 fixes the problem, but I’ve never seen a copy of the board. All the PCB info can be found in the above comments by alex_mp

  • mecano

    you can get a pcb via oshpark using the gerber file Jason kindly provide here also be sure to read his interesting post about grounding the adapter on his blog.

    • For those looking to just buy a board, I added my design to the “shared” section at … the permalink is .

      I haven’t done anything with this design in quite a while, but I can say the board I built a couple years ago is still working. That funky problem with the grounding doesn’t seem to have resolved the issue I was having with the monitor shutting off, and it seems to do with hot weather (no problems all winter in <70°F indoor temperatures; problems start in summer … hmm …)

  • Rukshan

    Hay Tony, thanks for your advice and all other things.i made as you said. and also can i try this by connecting a VGA to DVI connector to your gadgets DVI port?? is it work??
    ADC –> DVI –> VGA ???

  • Smith
  • june toda

    Hi, my name June Today. I have 2 Cinema display with your introduced ADC to DVI wiring, and I have been using the display with Mac Book without any problems. Recently, I have get the powerful Mac book Pro that provide two thunderbolt connecter.

    So, I got the mini-port to DVI cable to connect my Modified Cinema display. Unfortunately, I cannot get the any good result, and get just black screen.

    So, If you have any enhanced idea to connect Thunderbolt to ‘Our’ modified Cinema display, Please tell me the additional wiring.

    Best Regards, June toda.

    • Hi June,

      I’ve seen the same issue when connecting my ACD to my MBP through a displayport to DVI adapter. I’m not sure what the problem is, but if I had to guess I would say the problem lies in not having all the pins wired up correctly and therefore making the displayport adapter not switch into DVI compatibility mode. I wonder if the one of the printed circuit boards people have made works or maybe the official adapter.


  • Guillaume


    I’m Guillaume from France.

    I just found your website, and I’m looking about a adc board !

    I have two adc screen and i need to plug them on my dvi Mac

    Do you sell the board ?
    Could you send 2 board to France.

    I already have adc and dvi cônectors.

    Thx to let me know

    Best regards.

    Envoyé de mon iPhone

    • Hi Guillaume,

      Unfortunately, I do not sell any boards. You can read through the comments and get a copy of the design. There may a company in France that can have them printed for you.

  • Hi Tony, i bought an acd cinema display and tried to use it with a dr. bott dviator which i connected to a dvi to thunderbolt adapter. and then to my younger macbook. the dviator works fine with my old macbook that has a dvi plug. but with this two adapter setup the screen stays black. do you have any idea why? maybe i could use your mod to make it work with my younger macbook?

  • Edward Vayne

    Hi, since I have a formac-display with extra power-supply and usb, as you can see on the picture, I want to ask: Do you think I can overcome the compatibility-issue to normal DVI by just removing the rounded edges?

    • Do you mean cutting the round shield off the ADC connector? The answer is no. The ADC connector has a different pinout from DVI. You can see that from the table and wiring diagram in the post. Unfortunately, the only way I know to go from DVI to a monitor with an ADC connector is to buy an official Apple ADC-to-DVI adapter, find a Dr. Bott DVIator adapter, or build your own using the instructions in the post or getting a PCB printed like one below in the comments. Another alternative, if your brave, would be to cut the ADC connector off your cable and solder a DVI connector on.