MP 1,1-5,1 MacPro 4,1 won't start/boot

[Mojoxer]

I recently bought a MP 4,1 (W3520, single CPU only) of unknown provenance that will not start up. Symptoms:

• All fans start spinning (PS, PCIe, Front, CPU, Back) - slowly
• Power light lights up
• Diag LEDs - 5V Stby is Amber in minimum Config
  • no OVRTMP LEDs lit or light up
• CPU light on CPU tray flashes on power button press
• With CPU cage in:
  • PSU PWROK -green
  • 5V STBY - amber
  • EFI DONE - green
  • GPU OK - green
• NEVER chimes
• Without RAM
  • No Flashes on Front Light
  • No LEDs on RAM tray lit
• With RAM
  • Same as above
• Keyboard never recognized
  • Cannot reset PRAM
• Motherboard PRAM battery replaced
• PCIe cards tried
  • NVidia GT 120
  • NVidia 7300GT
• Never reaches any boot screen.

My suspicion is some sort of FSB or RAM issue. Any other ideas or suggestions to fix this, or is this one just a good machine for spares?

 

[840quadra]

Have you pulled the processor tray and inspected the install of the CPU itself?

If shipped or knocked around it is slightly possible that the CPU was partly unseated. Only issue with pulling it, is to ensure that it is properly.

May also want to check to ensure the correct RAM type is installed. My experience is only really with the 3,1 and 4,1 dual processor systems, so I am a bit lacking in some of this skill.

 

[Macschrauber]

Front Led should flash without ram.

Gt7300 dont works in a 64 bit efi machine
Gt120 should.