One of my nodes died last night. It's got a Corsair GS700, AsRock 990FX Extreme 3 mobo and an AMD FX 8150 cpu. The mobo and PSU are 2 years old, whereas the CPU is over three.
In it's full configuration, it refuses to turn on. There's no indication that there's any power. No lights, no fan movements, no beeps.
I checked the PSU, and it's fine.
I then discovered that if I only plug in the 24-pin motherboard PSU connector, but don't attach the 8-pin EDS CPU power, the computer behaves as if there's power i.e. all fans, including on PIC-E VGA card, spin etc.
There's no output though, and no POST beeps.
Plugging in the EDS/ATX12V1 cable again leads to a dead system.
Removing the CPU or RAM still yields a dead system (not sure what a mobo without a CPU is supposed to do i.e. whether it's supposed to POST. Either way, it's dead).
The CMOS battery tests fine with a DMM. The EDS/ATX12V1 output yields 12 V on all four yellow pins.
The power button is obviously working given that the system 'turns on' when the EDS cable is unplugged.
So it's down to the MOBO or CPU being faulty.
I've ordered a POST card and a CPU socket tester, and will update when I've done further diagnostics.
UPDATE 18/11: I put an old Phenom II in the socket. System still won't light up. This points towards the motherboard being dead. That's not a bad thing as the mobo might still be under warranty.
Lindqvist - a blog about Linux and Science. Mostly.