TLDR; need a pinout for the ribbon cable of the 820-2136-A Audio Board
I bought a Mac Mini to replace my 2007 20" iMac (A1224). The Mini is plenty powerful with its new quad-core i3, RAM is upgradeable, SSD is blazing fast. Now if it only had a display, speakers, microphone, camera, optical drive, extra HDD, SD-card reader and a TimeMachine drive but no cable-jungle, just something as nice and compact as my old iMac. ... Which, incidentally, has a perfectly fine display, speakers, microphone, iSight, Optical drive, HDD and space for a TimeMachine drive and a card reader!
For funny money, this driver https://www.ebay.de/itm/153176958307 converts the LCD panel of my iMac into an HDMI monitor. It comes without power adapter but luckily the PSU of the iMac has unconditional 12V, it powers both the diplay, the HDD and (through a 1$ buck converter) the USB hub and accessories connected to it (e.g. iSight).
I am half way through and all looks good... But doesn't sound very good. The above linked display-to-monitor circuit is correctly recognised by the OS as an audio output device and plugging a headphone to its jack socket produces sound as expected, by I can't control the volume. And I need an amplifier for the inbuilt speakers. And I still need to connect the microphone. Perhaps an USB soundcard and a PAM8403 amplifier would do the trick, but isn't the original Apple Audio Board (version 820-2136-A) just the same thing? It has a ribbon cable to connect it to the main board, if only I could convert that to DC+USB somehow...
Any help would be much appreciated!