[92] Apple Mac Pro (early 2008, 8-core) - No video or boot 

We managed to get this very old Mac Pro to boot after nearly three hours of trial and error troubleshooting.
The issue that was preventing the computer from booting was a bad memory riser / daughter board. After moving the RAM to the other riser, the computer would boot, but the video card would not display the desktop. After a bit of faffing around with other video cards and updating drivers, it started working correctly.
Music credits:
14:54 - "Switch it Up" by Silent Partner

Наука