[_underscore_]

Hello, I've had really weird lockups and crashes on this machine and I'm trying to find out if the PSU is at fault.

The machine is a Compaq S4000v with a 250 Watt Bestec PSU, running Ubuntu Linux. (the machine has to be like 4, 5 years old) previously the hard drive failed, that was replaced.

The problem is that occasionally, for no apparent reason, the computer locks up. Completely. It does not respond to anything. In addition, once rebooted, the BIOS tells me "Keyboard not found", or, more recently "detecting IDE drives ...". These are usually solved by rebooting.

I've ruled out the memory as I've run memtest86+ several times for hours with no errors.

I set up some monitoring software to tell me the PSU's voltage to try to get some indication if it is the cause.

The numbers I got where:

Originally Posted by lm_sensors

Sun Oct 26 09:41:03 CDT 2008
it87-isa-0290
Adapter: ISA adapter
VCore 1: +1.50 V (min = +0.00 V, max = +4.08 V)
VCore 2: +1.84 V (min = +0.00 V, max = +4.08 V)
+3.3V: +3.30 V (min = +0.00 V, max = +4.08 V)
+5V: +4.95 V (min = +0.00 V, max = +6.85 V)
+12V: +11.58 V (min = +0.00 V, max = +16.32 V)
-12V: -1.22 V (min = -27.36 V, max = +3.93 V)
-5V: -9.00 V (min = -13.64 V, max = +4.03 V)
Stdby: +4.81 V (min = +0.00 V, max = +6.85 V)
VBat: +3.33 V
fan1: 1383 RPM (min = 0 RPM, div = 8)
fan2: 1110 RPM (min = 0 RPM, div = 8)
M/B Temp: +36.0°C (low = +0.0°C, high = +60.0°C) sensor = thermal diode
CPU Temp: +28.0°C (low = +127.0°C, high = +75.0°C) sensor = transistor
Temp3: -55.0°C (low = +127.0°C, high = +75.0°C) sensor = transistor

Are these numbers good? What concerns me is the -5V right now, from what I understand the -12V is find since that's not used, but the -5V doesn't make much sense.

Thanks,
Isaac

[BG-0]

If it's ATX sized, just buy or borrow a new 300 W, for example Sparkle brand PSU to confirm it being or not being the reason for this.

[_underscore_]

I don't think I have one on hand, so that might take a bit. Do you know if there's anything I can do in the mean time to narrow this down?

Thanks

[BG-0]

Well, motherboard and CPU might also be responsible... No idea how to test... Might want to try running prime95 to see if it reports any errors or warnings caused by the CPU.

[_underscore_]

Now running mprime...

[_underscore_]

mprime doesn't seem to turn up anythinwrong, I suppose it must be the PSU?

Does anyone know if the -9V number on the -5V rail is normal?

I'll probably go ahead and replace the PSU.

Thanks for your help