I have red to 3 years old post and I face to same problem. After reaplacing shortened PSU with new one, after start - no beeps, no on board vga or no external graphic card output, no hard drive operation, no keyboard lights. I need to confirm that power supply system is OK. Here are my readings:
* purple pwr of constant 5,25 V; power on constant 5,25 V
* green pwr of constant 5,18 V; power on constant 0 V (it decreases quick after start an after switch it increase quick too)
* gray pwr of constant 0,02 V; power on constant 5,4 V (it increases quick after start and quick fall after switch of)
* orange pwr of constant 0 V; power on it increases slow (2-3 seconds) to 3,58 V and it stays constant, after switch of falls quick down
* red pwr of constant 0 V; power on constant 5,4 V (it increases quick after start and falls after stop quickly)
yellow pwr of constant 0 V; power on constant 12,4 V (it increases quick after start, after switch off it falls to 2 V quickly and in 1 minute it falls to 0 V)
Also is the power supply system OK? Hard drive (read/write opereation, noise, sectors - zero errors) is OK. Memory module are OK (memtest).
Also is it motherboard or CPU issue? (MB AsRock ALive NF6G-VSTA, CPU AMD Athlon 64 X2 ADO4200IAA5CU NED GT.