Is my PSU faulty?

My PC has recently started freezing. I've narrowed it down to the following facts (using DDR RAM):

2 modules in Single Channel mode, it takes some hours to freeze.
1 module in Single Channel mode, it takes some hours to freeze.
2 modules in Dual Channel mode, it takes about 2 minutes to freeze.
2 modules in Dual Channel mode, with memory speed underclocked, it takes some hours to freeze.

Memtest running for 10+ hours for each module shows no errors. I've also tried with another pair of RAM and the results are the same. Also, about 1 month ago, 1 HD and 1 memory module were broken and had to be replaced.

Are these good indicators of a faulty PSU? It shouldn't be a heating issue as the temperastures are OK and the PC has multiple fans working.

Specs:

mobo: ASUS P5GD1 Pro
CPU: Pentium4 3Ghz (Prescott)
PSU: BeQuiet! 350W
RAM: Patriot 2x512MB DDR400 (also tried with Corsair 2x1GB)
OS: Ubuntu

Edit:

Temperature readings: CPU 48ºC, MB 37ºC, graphics card 48ºC. Chipset heatsink passes the "finger test" and fans are OK. Using cpuburn, temperatures raise quite a bit but there's no freeze.

Additional info: in dual channel mode, if I boot into console-only mode, the system doesn't freeze right away, only after some time (say, 30 min.). However, the system freezes immediately the moment I start the desktop environment (GNOME).

Conclusion:

The problem is still present with a different PSU and also after trying different components for everything except for the motherboard and CPU. Between these two, perhaps it's most likely a motherboard problem.

noup

Posted 2011-08-21T12:59:35.113

Reputation: 123

Answers

First of all, 10 hours of memtest does not yet guarantee you'd spot the error. Some errors can take days to be revealed.

However, as you've cross-tested with another set of memories, it sounds like either motherboard or PSU would be faulty. Because memories and their settings affect the freezing frequency, I would first suspect the motherboard, especially since on P4 it's the chipset that controls the memories.

Are you running the latest BIOS available to your motherboard?

Check also chipset temperatures; if the heatsink is too hot to keep finger on it, then it's, well, too hot. Fans die over time, so it's possible the airflow in the case has lowered too much causing the problem. You can check that the fans work properly by putting a wooden pencil between the blades and then checking that it starts rotating right away; if it looks like the fan has trouble starting to spin again, the bearings are dying and it's time to swap the fan.

Zds

Posted 2011-08-21T12:59:35.113

Reputation: 2 209

Thanks for the answer. I'm running the latest stable BIOS, there's a newer beta (dated 2006) which I'll try to install (using Linux and the Asus update tool seems to be Windows-only). – noup – 2011-08-21T13:31:02.870

Many other board can update BIOS from USB stick, and if not that, you can use FreeDOS and the DOS burn tool. As long as you get the raw BIOS binary at your hand, standard BIOS flash programs work. – Zds – 2011-08-21T13:40:36.903

A good find, the BIOS actually has an update tool itself (Alt+F2), just needed to have the ROM in a floppy. But unfortunately, this didn't fix the problem. – noup – 2011-08-21T19:40:59.530

Edited the question with more info, all seems to be fine with heatsinks and fans. I'm feeling a bit more inclined to a problem with the MB now. – noup – 2011-08-21T22:33:39.303

Ayup. On P4 practically all data goes through the chipset (on motherboard), so if it has serious problems, it can hang the system all alone. Ie. all IO, including memory access from processor goes through the chipset. – Zds – 2011-08-22T08:27:38.143

Heat on chipset might be the problem. Check your graphics card's fans & heatsink, also check the motherboard's heatsinks.

Nime Cloud

Posted 2011-08-21T12:59:35.113

Reputation: 923

I've got faulty motherboard that freezes regularly, I've searched the net and found similar cases. An onboard graphics chipset with heatsink without a fan was the reason. – Nime Cloud – 2011-08-21T14:04:48.510

Should that have an influence on using a single vs dual channel memory configuration? – noup – 2011-08-21T19:46:27.170

If it passes the BIOS test, no. – Nime Cloud – 2011-08-21T19:51:19.193

Sorry, I hit Return by mistake and wasn't quick enough to add the rest of my reply. Was going to say that all fans seem to be working fine, and besides the graphics card and CPU, there are 2 in the front and 2 in the back. Also the case is open. Graphics card temperature also seems normal (45ºC), as does the rest of the system. – noup – 2011-08-21T19:55:37.817

I know. I just told you what I've experienced. I've got tons of fans and open case and used an extra home fan. I've added extra fan to heatsink then it has be frozen seldomly. At the end I replaced the motherboard. – Nime Cloud – 2011-08-21T20:14:16.423