08 November 2010

Apple Display Hack Followup

Here is a link to the original post: http://doesntexistat.blogspot.com/2010/11/hacking-apple-studio-display.html

Intro, Power Supply

So this past week was exams week, which means that I did not get much time to work on the project. After exams were over on Thursday night, I opened the 24V 1.5A power supply that I got from ebay! The cute power supply is pretty small; about the size of 5x7 photograph. There are terminals for AC +, AC -, AC Gnd, 24V +, and 24V -; you unscrew a screw which secures a plate, which in turn sandwiches the wire in the middle of said plate and the power supply unit itself. I then stripped one of my many computer power cords so I could use a 3-pronged plug. Most 3-prong plugs have black as L (line), white as N (neutral), and green as ground. No soldering or nonsense was needed to wire, since the only effort to wire up the system was unscrewing five screws and inserting the wires in between the plates and the unit itself. Before I wired up the monitor power cables to the power supply (and after I had attached the AC power cord), I measured the output with a voltmeter, and sure enough, it read 24.5V! Perfect.

Wonky Connections

I then wired up the monitor, plugged in the setup, and powered on the system. Sure enough, the monitor came to life! Upon closer inspection, I noticed some pixels that were spazzing green (i.e. flashing green and the proper color). This was probably a problem with the cable connection; I smacked the mess of wires and the number of spazzing pixels reduced.

The spazzing goes away if I squeeze the proper connections. This confirms that some connections are loose. I can temporarily fix the problem by holding the connections with a binder clip, but will resolder and/or reshrink the connections once I get a soldering iron in my room. There is no way I am lugging the monitor 1 mile across campus again.

Setting up a ghetto dual screen setup in the middle of a dorm (Random Hall) kitchen warrants weird looks!

USB & Hotplug

Apparently USB was always working. I finally tested it today with an Apple USB mouse. It's good to know that the monitor extracts/produces/ the +5V required internally. I still have yet to figure out hot-plug support (I guess it is a matter of soldering two wires together).

Display Brightness

I hadn't really thought about this until I skimmed through the bit-tech thread for the clean version of this hack. As all Apple display owners know, the brightness is controlled through software (System Prefs on a Mac), and the button on the display is more or less an app launcher for System Preferences. I confirmed that pressing the button works -- it brings up System Prefs to the Display pane. Dragging the display brightness does change the brightness!

Other people mentioned that the display will draw significantly current at a high brightness than at a low brightness. When I tested the display (at full brightness) with the lab power supply, it drew less than 1.5A, so no worries there.

Breakout Box

I thought about making a breakout box as the true solution to this problem. I was fortunate to find a video card with a female ADC port in the dumpster. In theory, I could desolder that, create my own PCB board, and solder the necessary parts on (female ADC port, female DVI port, connection to power supply, USB cable). Unfortunately, desoldering the ADC port from the video card was crazy evil (especially at 12:30am), so I stopped working on it for the evening. Perhaps the desoldering tool needs a smaller head (it was one of those powered heat+vacuum tools). I will give it another shot when I return to MITERS.

Miscellaneous

One of my friends also got a 15" version of this monitor and creatively mounted it on his bunk bed after stripping off the acrylic (which is equivalent to unscrewing seven hex screws). He is also planning to do this hack! I am happy.

Feedback and Q&A

I also read much of the feedback to this hack. Thanks all who appreciated it. I do realize that this hack is not original (in fact I did not claim to be the first one to have done so since I linked to someone's pinout guide in the main post), but I do claim that this is my first hack. I do want to congratulate WarriorRocker for his very clean and Apple-esque Apple Studio Display hack.

Now, to answer some questions/feedback:

Q: ...pinouts.ru...
A: Yes, I'm well aware of it. However, soldering the pins on the plug to wires is tricky, and since this is my *first* time soldering, I'd rather do something more manageable. I'm sure the hack will be a lot easier had I just connected corresponding pins with wires. Thanks anyway!

Q: 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.
A:  Yes, you are missing DDC Clock (ADC pin 9) and DDC Data (ADC pin 19). Your power supply should be more than fine; the monitor is rated for 50W.

Q: Other Pins <=> Colors on the DVI fragment
Is there any number pin number?
Dvi or adc pin number ?????
A: The DVI pin numbers are on the left of the chart. Basically that chart was a listing of all the leftover wires after I had soldered everything according the the main chart. Apologies if that was unclear.

Again, a big thanks for all who thoroughly read through the post and appreciated it!

23 comments:

  1. The amperage of a power supply cannot be "too high" - The monitor draws what it need, no more. Basic electronic knowledge.

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  2. Cherry, DDC clock and date were the missing links I was looking for! The PC now detects the studio display. However, the monitor itself is not displaying anything. The power button only glows dimly and pulses brighter briefly if I touch it. Did you have to do anything special to power it up? Any further advice would be greatly appreciated!

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  3. And zapro, thanks for the informative, if not slightly snarky comment ;)

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  4. Thanks answerring..
    please Need more information.
    ADC pinpoint to DVI pinpoint.( NON COLOR)
    Thanks.

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  5. Hi jerom,

    What do you mean by `non-color'? Are you referring to the loose wires (the shielding)?

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  6. hello.
    I want ADC pinpoint number to DVI pinpoint number.
    Thanks.

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  7. Moniter does not work.(power off)????
    What can I do.(power on)

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  8. Hi jerom,

    Could you describe the situation a bit more clearly? Also, the ADC pin numbers and DVI pin numbers are listed here (http://pinouts.ru/Video/apple_adc_pinout.shtml) and here (http://pinouts.ru/Video/dvi_pinout.shtml), respectively. Hope this helps!

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  9. jerom and I might possibly be suffering from the same problem, in that I can't seem to get the backlight to come on. I've been suspecting that I have a bad inverter, but if jerome is having the same problem, perhaps we are both doing something wrong?

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  10. Thanks for your help Cherry su.
    The monitor will work.
    Thanks again Cherry su.

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  11. Hey Jerom,

    Glad to hear that you got your hack working! Do you mind sharing what you did? A work log would be great, too.

    Happy hacking!

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  12. Hi Cherry su,
    you´ve done a great job on your Studio Display!
    I´ve tried to hack my old Studio Display to every thing works fine except i´m missing the red colour completely...Do you have any idea why it is missing ?

    Thanks in advanced

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  13. Hi cherry su,
    first thanks for the descrition on how your hack work,Ithink you´ve done a great Job with it.
    I tried that hack with my old 17" Studio Display, so far everythink works fine except I´m missing the red colour,the hole screen ist Blue/Green, I already checked all connection and they´re fine.
    Do you have any advise whats the problem could be?

    Thanks in advanced!

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  14. Argh!
    I have hacked this monitor up to a DVI-D Single Link cable and it didn't work!
    The DVI cable doesn't have a wire connected to the C5 pin so I soldered a wire onto the graphics card C5 pin and ran that to the Brown wire in the ADC cable!
    However it's still not working - Just the power light is on (yellow) and no video :(
    I haven't connected any of the naked wires in the shielded video triples. Should I have?
    I don't understand why this doesn't work - I've squeezed all of the solder joints under the heatshrink but still no video.
    Does anybody have any useful tips that I could try because I think I've exhausted every option.
    Jake

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  15. Hi,
    I have already posted in the original thread. Some conclusions here:
    (1) The C5 cable can be left unconnected. Seems it is not necessary for digital input.
    (2) Hotplug: Connect the "Hotplug" wire to the "+5V" wire with a 1kOhm pull-up resistor. This indicates that EDID information is available and hotplug is working.
    (3) I connected my display as a second monitor, and after the first start it stayed black. I just had to switch off the "display mirroring" and select the right display resolution (1680x1050 in my case), then the display came up with the right picture.

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  16. @JeanLuc7: Thanks for your advice! I'll update my posts after I get back to MIT and test your suggestions.

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  17. "Unfortunately, desoldering the ADC port from the video card was crazy evil (especially at 12:30am)"

    In the mean time I decided to mod another monitor, this time with a breakout box as you proposed. I am aware of the problems with de-soldering multi-layer boards, so I went down with my dremel tool and cut lines between every single pin. This way I just had to de-solder pin by pin which was done in a quarter of an hour. What to say: the break-out box is ready and running :-)

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  18. hye i have (nividia)px7300gs 265mb video card with dvi port can this lcd connect with it ???
    or use adc to dvi connecter?

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  19. If you do this mod, then you don't need the adapter. Otherwise, you'll have to buy it.

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  20. Nice! Do you have a writeup or link to your project?

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  21. 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?

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