02 November 2010

Hacking the Apple Studio Display

I acquired a circa 2002 17" Apple Studio Display LCD in good condition from my friend and dumpster-diver-buddy Bayley Wang. The monitor is one of the top-notch 17" monitors: (Hey, it retailed for $999!) it has a superb IPS, or in-plane switching panel for unmatched color quality even by today's semi-professional standards (pros probably want 10- or 12-bit panels now). Unfortunately, this unit has an Apple Display Connector, or ADC, plug instead of the more standard DVI plug. On the flip side, the ADC is simply DVI + USB + 25V, so I could hack the monitor to use DVI! I looked on Google for previous hacks, but the only relevant documentation was a post and a PDF on the Apple discussion forums describing the ADC pinouts and their DVI equivalents. Having nothing better to do, I decided to splice a spare DVI plug onto the monitor!

Hacker food = McDonald's. Yup.

I began by cutting off the ADC plug from the single wire the came out the back of the monitor and then proceeded to strip off the rubber sheath, cut off shields, and strip the internal cables. The actual cables were 26-gauge wires -- they were very thin and looked very fragile! I used a magnifying glass to help peel off the shielding. Some of the internal wires were grouped and additionally shielded; I exposed them at a shorter length to prevent cable confusion (there were multiple cables of the same color). I repeated the process for the DVI cable: first cutting it in half, then stripping the wires, and finally stripping the wires which were enclosed in a further layer of shielding. Stripping all the cables took a good hour and a half.

The next item in our agenda was to find out which wires corresponded to which pins on the DVI wire fragment. I was not quite sure what to do initially, but a MITER gave me the following tip: Apparently the ohmmeter has the nice property of displaying some odd (i.e. zero) resistance when the positive and negative leads are connected without resistance. I tested all the pins and all the wires and constructed the following charts (note: these colors may be different for your DVI cable!):

Main correspondence table

ADC colorDVI Pin & Color (if none, function)
2x thick red+25V
2x thick blackGnd
very thin dark brownC5
very thin orangeLED
light blue 7 yellow (single)
yellow6 white (single)
green (twisted w/ white)USB D+
white (twisted w/green)USB D-
black (near USB Data)USB return
light brown (t. w/ white)24 white (white, blue)
white (t. w/ light brown)23 blue (white, blue)
white (t. w/ orange)2 red (red, pink)
orange (t. w/ white)1 pink (red, pink)
pink (t. w/ white)9 brown (yellow, brown)
white (t. w/ pink)10 yellow (yellow, brown)
white (t. w/ black)18 green (green, black)
black (t. w/ white)17 black (green, black)

t. = twisted
(color1, color2) = color1 is in the same shielded group as color2

Other Pins <=> Colors on the DVI fragment

11naked w/ yellow, brown
16light brown (single)
14dark brown (single)
15black (single)
3naked (red, pink)
22naked (blue, white)
19naked (green, black)

single = not in a shielded group

Male DVI-D (single link) pin numbers:


The --- pins represent unused pins; these pins are for dual link connections only.

I was left waiting for quite a bit because I didn't know how to solder and one of the MITERs who graciously volunteered to teach me, Dane, was busy with his project. After he was done, he soldered one of the wires on the monitor end with the corresponding wire on the DVI cable fragment while I watched from the side. Then he placed a heatshrink over the freshly soldered wire and blew it with a heat gun to prevent the conjoined wire from shorting the other wires. I then sat down for what seemed to be an hour and concentrated on soldering all the pairwise wires. The end product was a great big mess; Charles Guan, the MITERS god, felt sick to his stomach just by looking at it! Everyone doubted that my hack would work, but I had a sliver of hope that my first real electronics project would succeed.

After I was finished, I showed Dane the end result. He suggested that I should solder the shields (the naked wires in the shielded groups), too. I finished soldering rather quickly, heatshrinked them, and reported back to Dane. We then connected the monitor to the lab power supply, dialed it to the Apple-specified 25V, and connected the alligator clips to the red and black wires on the monitor. Dane touched the capacitative power button, which pulsed at the touch. I connected the monitor to my laptop, went into System Preferences, and hit `Detect Displays.' The monitor then came to life in mirror mode!! My five hours of hard work paid off!

 IT WORKS!!11!!oneone!

Mess of cables

Other notes:
  • USB does not work. I'll get that working this week. [EDIT] A friend suggested that the monitor might internally make the +5V required for usb, so I'll have to test it this week at MITERS since I don't have the power supply in my dorm. USB does work -- see the follow-up.
  • Hot-plug display detection doesn't work. I'll get that working this week.
  • I will consider making a breakout box instead of hacking the monitor cable. One of these adapters costs a whopping $99 from Apple! 
  • The monitor runs fine on 24V and draws slightly more than 1A -- no need for 25V. I have already ordered a 24V 1.5A regulated power supply from ebay.
If you have questions and comments regarding this hack, feel free to leave a comment (Google account required)!

EDIT[2]: Here is a followup of the hack: http://doesntexistat.blogspot.com/2010/11/apple-display-hack-followup.html

EDIT[3]: Here it is in action: lame dual display and insanely excellent triple display


  1. The hacked wire doesn't look THAT messy (at least compared to some of the wiring I've seen in RADD), and who'd buy a $99 converter when they have wire strippers, soldering equipment, and something (which costs far less than $99) to use as insulation? ^-^

  2. http://pinouts.ru/Video/apple_adc_pinout.shtml

  3. Awesome - thanks a lot !!!!

    Too bad, you don't have a flattr-account.

  4. Hi there, nice job. I happen to be attempting the same thing and I seem to be running into a snag. The only video connections I've made are the 8 which come off the board - Clock +/-, TMDS 0+/-, TMDS 1+/-, and TMDS 2+/-. Is there anything else that is necessary for DVI to work that I'm missing? Also, I'm using a 24V 4A power supply, could the amperage be too high? The power button lights up and pulses but I don't even see a flicker on the screen.


  5. http://forums.bit-tech.net/showthread.php?t=188336

    Made this a few months ago, Apple Cinema Display ADC to DVI Conversion

  6. YES!! So glad to help sherry. its a heckuva 'intro to soldering' :)


  7. Other Pins <=> Colors on the DVI fragment
    Is there any number pin number?
    Dvi or adc pin number ?????

  8. Nice job on being quoted by lifehacker and nice USACO problems!

    Do you have any good resources for learning algorithms used on USACO? I'm currently a freshman at BCA. (I have experience with programming but haven't done much USACO type of practice in the past besides for going through "thepythonchallenge". I'm in the silver division. I'm developing an iPhone application but I want to do well in USACO so I can have something to show. Plus, its good practice)

  9. WOW.

    i jusssst came across the dilemma of junking my old display.. i don't have any soldering skills though... so please let me know if you decide to make a black box for this thing.. SOOOOO willing to give you money for this.

  10. Hey guys, I have written a followup post (which is now linked in this post at the very end) that includes some additional progress and replies to feedback. Hope you find it useful!

  11. Hi,
    I've not got a spare DVI cable just yet (I've ordered one).
    However, I've chopped the ADC connector off of the 17" Apple Studio Display and because i'm so impatient have attached a 24v 1.87A Macintosh PowerBook 45W AC Adapter that I had lying around from an ancient PowerBook.
    The power button lights up and glows brighter when it's pressed but is not the White glow that it looks like it should be in the pictures but instead is a definite yellow colour!
    Am I just being paranoid and should It be a yellow colour?
    Will it glow white when there's a video source attached or is it that the led is old and has turned yellow?
    Also, How have your experience's been with hacking this monitor up to a DVI connection been?
    Thanks in advance for any replies.
    Jake Turner

  12. Hi,
    Great work! I did this mod last weekend on a 20" ACD. In addition to your mod, I found out a few more things about the ADC cable:
    (1) As you already found out, USB is working with only 3 cables, leavnig out the +5V line. The backlight control is implemented over USB, so this works as soon as the USB cable is connected.
    (2) I left LED and Soft Power lines unconnected. However, the display automatically powers up when the machine is switched on. The LED stays off, but can be switched on manually. Don't know if the original Apple ADC adapter adds soft power functionality by simulating some action on the USB channel.
    (3) C5 was not available on my DVI cable, so I also left C5 unconnected. I took at look at a graphics card with only DVI-D output and found out that there was no connection from C5 to the card. Seems it is not necessary for digital input.
    (4) The DVI cable contains three additional cables with no equivalence on the ADC side - that's "Hotplug", "+5V" and "Ground (5V)". The ADC generates this 5V power on the logic board. But it is necessary to connect the "Hotplug" wire to the "+5V" wire with a 1kOhm pull-up resistor. The DVI specification says that with a voltage over 2.4V the "Hotplug" connector indicates that EDID information is available (which is the case with the ADC displays).
    (5) In my case a power supply with 24V/3A was more than enough, but I also did another mod on that display: I replaced the CCFL tubes with LED backlight, which significantly reduces the power consumption. Additionaly, the display does not heat up anymore.

  13. Is it possible to create an outside power source for the ADC monitor only.
    Instead of drawing off the Mac's power supply.
    Alleviating the strain
    without hacking off the cable to do so.
    If so would this be easy to do?
    and of course any suggestions on how?

  14. Hi CrazyMac, you are able to create an external power supply as I did. Instead of chopping up the cable, you would need to:
    1. find a female ADC port
    2. solder the power pins (see pinout diagram here: http://doesntexistat.blogspot.com/2010/11/hacking-apple-studio-display.html) to the external power supply (like the one I have, described here: http://doesntexistat.blogspot.com/2010/11/apple-display-hack-followup.html)
    certainly takes a bit of patience, but doable with a bit of basic electrical engineering knowledge!

  15. What I was thinking is to just create an external power supply for the monitor.But continue to use it as an monitor for an ADC equipped mac.I have always heard that the ADC monitors do put a strain on powersupply's.
    With out hacking up the cable.
    Cut the wire's for power from inside the monitor coming from the cable. Splice in a jack
    PLug in the external power supply.
    Now hopefully you have an monitor working on its own external power.

  16. Ah, I see what you mean. You could make a cable with a female ADC end and a male ADC end and, from the female end, split out the two power wires and hook that out to the power supply (obviously, don't also connect those to the male end). Thus your monitor will be powered by the external power supply and will not use the power supplied by the video card. The ADC to DVI adapter is similar; substitute the male ADC connector for a male DVI connector.

  17. I made a short tute copied from this one detailing my procedure in having hdmi cable instead of dvi:

  18. Can you please make like a detailed YouTube video and share a link with us or something? I Just got my 15 inch Apple Studio Display on eBay, and I do have a few DVI cables laying around, if I could do this then I wouldn't have to go buy a $150 converter box.
    Also, for the charger, could you just use any charger that's 24V or more? (I don't really know about electric stuff)

  19. Would you mind explaining the power source a bit more? I'm not sure what exactly I would need if I were to attempt this. Something like this? http://www.ebay.com/itm/24V-DC-1-5A-35W-Regulated-Switching-Power-Supply-/120964421436?pt=LH_DefaultDomain_0&hash=item1c2a0a973c

    Also, would it be easier to match up the wires if I got this adaptor? This way I would just have to match the male ADC wires to female ADC. http://www.newegg.com/Product/Product.aspx?Item=N82E16812116204

  20. The deal with the power supply is that you need something that outputs at minimum what the display wants; in this case, ~24V and a tad more than 1A. So yes, the gentleman you linked to probably will suffice.

    Yes, the adapter would help matching wires; all you would need to make is essentially a female to female ADC adapter.

  21. I'm thinking of upgrading the video card in my G5, but few cards are ADC... I was wondering if you had any information on what the pinouts for the connector on the G5 motherboard were.. It's a card slot type connector.  I could probably patch in the voltage & usb from that port to the monitor, and then use any card that will work in an Apple G5.. 

  22. Cool! thanks

  23. im left with a pink wire!

  24. If it's on the ADC side, then it should be soldered to pin 9 on the DVI side (see table). Hope this helps!

  25. Excellent effort Sherry Wu, thank you. I know this is years later but there are a lot of these beautiful old Apple monitors in the world and you have helped extend their lives. Don't know if I'll try it on my 25/27" cinema display, yet, its working thru an ancient Apple adapter box with an old Mac mini at the moment which has become very slow. So I want to hook it up to the PC laptop at work, I need more screen real estate there.

  26. If your laptop has a DVI connection, then you can connect the monitor to it via the box. Otherwise, you will need a USB to DVI DisplayLink adapter.

  27. Hey, I read your blog and I think t is an amazing hack for my old apple studio. I was just wondering if you got the hot plug display to work and if I were to do this hack do you think that a HDMI to DVI adapter would allow me to view my laptop with an HDMI output on the apple screen?

  28. Yes, this hack should work with a DVI (female) to HDMI adapter. Or, since HDMI is more or less a rearrangement of DVI pins, you can mod an HDMI connector instead of DVI.

  29. also because both the dvi and hdmi use digital signals!

  30. Hey I finished connecting the HDMI to the stripped ADC and I also got the hot plug to work! But the problem is that the image wont appear on the apple screen but my laptop does still recognize the apple studio display as being connected. It automatically adjusts to the recommended resolution and says Apple Digital Studio Display. Any solutions??

  31. 1. Does the display have power? You need to build a small power supply for it.
    2. Are you sure you didn't mix up the data pins?
    3. HDCP could be interfering, but i'm not sure.

  32. 1.Yes the display has power, when I touch the capacitive power button the led turns on and then fades away.
    2.I used this as a reference for my hdmi stripped wire
    3.I don't know what HDCP stands for or what wire it travels through.

  33. http://www.hdmi.org/installers/insidehdmicable.aspx

  34. That looks fine; it seems to agree with pinouts.ru: http://pinouts.ru/VideoCables/hdmi_dvi_cable_pinout.shtml

    HDCP is a form of copy protection at the hardware level. Basically, if your computer doesn't like a display because it doesn't have HDCP, then your computer will not output any image to the display. https://en.wikipedia.org/wiki/Hdcp

  35. I tried to connect it to 2 different laptop but it still doesn't show any image.

  36. Any more suggestions, is it possible that the lcd monitor doesnt work even though the power LED is on. when you plug your power supply to your monitor without plugging it to a video source does the power light pulse at touch and then fade away

  37. I think it did (don't have it handy to test); you might have to click ``detect displays'' in settings. However, I'm skeptical of that since your computer already knows about the display :S

  38. did you connect it to a windows machine or a mac?

  39. Worked on Mac, Windows, and Linux. Are you sure you don't have a loose connection somewhere?

  40. I have pink, orange and a brown wire not connected to anything did you leave it dangling?

  41. If those are from the Apple display, then that's not good...

  42. yea they are from the display because i dont know what the LED is on the chart. Could please explain?

  43. 1) I have orange, brown and pink wires dangling off of the adc wireand I dont know what to plug them into.
    2) I dont know what the LED is on the chart and what wire I have to attach it to.
    Thanks in advance!

  44. LED from the chart is: very thin orange

    It might help to undo all the soldering, look at pinout diagrams from pinouts.ru, match the wires *very carefully*, and redo the soldering.

  45. My question is that what did you plug the LED wire to, if it isnt on the dvi?

  46. None, as indicated in the photo with the sheet of paper.

  47. my probleme in apple HD 23"

    i dowt know color pinout

    if can you give me a correct color pinout of ADC cable

  48. and wish DVI cable ???
    DVI-D single link or dual link
    DVI-I single link or dual link

  49. I am having trouble locating C5 on my dvi cable. i have found the pinout but when i try to do a resistance test to find what wire it coresponds to, none of them show up. is C5 just the outside copper wire that grounds the entire cable or what?

  50. hi i am trying to connect hdmi instead of dvi as well but after completing the connections the display did not show anything for me. could you share the details i could not open the link you mentioned.

  51. Do you think it would work to just go into the display, find where the power goes and wire that to a power supply. Then, simply use a dvi to adc adapter to get the video signal?