Ersterhernds iMac G5 20 Inch A1076 Project

[carl]

I'm not sure if you can somehow 'trick' the system or not. Even if you can, is there a means to recognize the 2nd monitor in OSX or the upcoming macOS

Well, by sort of accident I found a solution. Plugging and unplugging the lcd screen to test, I damaged one of 3 ribbon glued connector. It amazes me how all this stuff works. What looked like just a translucent plastic piece it had imbedded like 50+ contact lines. There it came to me. What if i take that paper thin LED inverter board and find a home inside the iMac. Problem was I needed to make sure it auto booted cause screen only comes alive at log-in screen. A bit longer to boot, but I got there. So I got it to work. However the color is off. There is a green tint. Did I mess up the HDMI wiring, or could my panel sitting for so long just doesn't have anymore. There are no artifacts, jitters or anything, just the color greenish. I swear when i first discovered this lcd trouble booting in windows, the screen was fine.

 

[ersterhernd]

Well, by sort of accident I found a solution. Plugging and unplugging the lcd screen to test, I damaged one of 3 ribbon glued connector. It amazes me how all this stuff works. What looked like just a translucent plastic piece it had imbedded like 50+ contact lines. There it came to me. What if i take that paper thin LED inverter board and find a home inside the iMac. Problem was I needed to make sure it auto booted cause screen only comes alive at log-in screen. A bit longer to boot, but I got there. So I got it to work. However the color is off. There is a green tint. Did I mess up the HDMI wiring, or could my panel sitting for so long just doesn't have anymore. There are no artifacts, jitters or anything, just the color greenish. I swear when i first discovered this lcd trouble booting in windows, the screen was fine.

There's likely a short or inconsistency in your HDMI wiring. The R G and B channels occupy HDMI pins 1,2,3 (red) then 4,5,6 (green) and finally 7,8,9 for blue. If its a green hue you're getting, I would suspect that your red channel is in need of a little fix.

Shouldn't be too difficult to sort out.


Cheers!

 

[carl]

No luck on the short. Unwrapped and checked and double checked connections. Maybe its the block itself. Im having another shipped. What about female section of hdmi cable. Have u tried splicing wires instead of soldering?

 

[ersterhernd]

S

No luck on the short. Unwrapped and checked and double checked connections. Maybe its the block itself. Im having another shipped. What about female section of hdmi cable. Have u tried splicing wires instead of soldering?

Soldering the tiny wires I'm the original G5 video cable was the only method I used. I believe there's a thread somewhere in this forum where someone designed a pcb to connect the G5 cable to HDMI, but I'm unsure if it was ever successful or not.

A pcb plug n play solution would be ideal.

 

[carl]

Success!
Little update: I could not find the short. However I noticed my JB weld tube say "steel" on it. Could that have been the cause? Maybe, so since my solder skills have improved, and had bought a finer tip I was able to salvage the pcb HDMI jack I had trouble with, and gave it go again. I soldered 2 leads right to the pins since I had no more pads on it. This time I used a clear epoxy to strengthen. When I fired up, the green hue was gone. Now onto the next to sort out. Basically it uses the iMac as a second screen with this setup, unless I can figure out and connect the lvds directly.

Ersterherd, a thread of yours of the NUCImac G4

EDIT # 2: Thanks to MacTester57's advice, I've installed a simpler and totally silent solution (no relay 'click' sound) shown below using a BC547B transistor.

Would this work on these iMac G5?

 

[ersterhernd]

Success!
Little update: I could not find the short. However I noticed my JB weld tube say "steel" on it. Could that have been the cause? Maybe, so since my solder skills have improved, and had bought a finer tip I was able to salvage the pcb HDMI jack I had trouble with, and gave it go again. I soldered 2 leads right to the pins since I had no more pads on it. This time I used a clear epoxy to strengthen. When I fired up, the green hue was gone. Now onto the next to sort out. Basically it uses the iMac as a second screen with this setup, unless I can figure out and connect the lvds directly.

Ersterherd, a thread of yours of the NUCImac G4

Would this work on these iMac G5?

I tested it unsuccessfully when I first drew my G5 power map. I chose the relay to completely isolate the NUC from the Apple psu. The two do not share any common wiring.

Your mileage may vary. Perhaps try to turn the psu on with 5v.

Don't destroy your hardware trying though.


Cheers

 

[carl]

I tested it unsuccessfully when I first drew my G5 power map. I chose the relay to completely isolate the NUC from the Apple psu. The two do not share any common wiring.

Your mileage may vary. Perhaps try to turn the psu on with 5v.

Don't destroy your hardware trying though.

I don't quite understand, so your saying that resistor option did not work then. I have the 5V relay working on a 3V line. It works fine, I just hate that loud click. Maybe not so bad when closed. I can understand better isolation with that setup.
Small update: I'm almost there, I hope. I tried that step-down module to split standby power. The problem I encountered was the DC pin patch cable is a 3 wire and the module is only 2. It held 19.5V nicely. I left the blue not connected. At boot it beeped, probably gave an error. That blue cable I understand is a communication cable, so it needs to be connected. So it looks like I need to put in PSU power brick after all. I replaced the headphone jack with a male to female patch cable. The quality I got is not good, and wished I had tested before welding in. Plugging in and out is difficult. What I forgot was I'm dealing with laptop MB so having connected inside means speaker output is auto disconnected. I'm hoping if I get a USB audio adapter like you did will allow me to use the speakers as well and fix this issue. I could not get the laptop webcam to work by USB. I'm not sure why. Maybe cuz it part of the LVDS connection scheme.

 

[ersterhernd]

Too bad about the PSU. Grest try though.
USB Audio is by far the easiest way to go. Both installation and future updates of MacOS.
Keep going!

 

[carl]

USB Audio is by far the easiest way to go. Both installation and future updates of MacOS.

Dumb question on audio adapter. Since I don't have many ports can I splice USB male part from audio adapter into existing line? Will there be conflict if I then plugin a flash drive or something on that port?

 

[ersterhernd]

Dumb question on audio adapter. Since I don't have many ports can I splice USB male part from audio adapter into existing line? Will there be conflict if I then plugin a flash drive or something on that port?

Splicing USB? I wouldn't.

Perhaps one of these will expand your capacity as required. I've used this product in many of my NUC bulids. Works excellent. Connect 2 existing USB ports to it (or a double usb header) along with a 5v supply, in return you get 8 powered usb ports that are simultaneously managed by the PCB.

http://www.ebay.com/itm/NZXT-IU01-USB-Expansion-Board-Internal-External-/272134534775

Cheers
Ersterhernd