PC Randomly Cuts Power

[KnickNut3]

Rig:

XP 2400+
NF7-S v2.0
1GB PC3200
Radeon 9800 Pro
COOLMAX CX-450B 450W

I had this problem before with a PC that had half the same componenets, but this one has a different PSU so I'm not sure what's up:

The PC has been increasingly randomly cutting power. What I mean is that the computer with randomly cut out in the middle of doing something, immediately no output to the monitors, but the fans are still on. Hittin the power button does nothing, I have to reset or turn off the switch in the back.

Before it only happened when I was running poker statistical software overnight with CPU intensive SQL calculations. Today it happened while watching an AVI file. I rebooted and it happened again as it was booting back up, then again in the BIOS. I assumed it was a heat issue, so I left it off a bit, increased the ventilation for the PC (It was hidden behind a desk.) However, it just happened again 6 hours later, with more ventilation and the room 10F cooler.

Any ideas? I could use the help. No overclocking, all voltages set to stock levels. Here's the MBM log leading to the last crash.

+---------------+---------------+----------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+
| | | | Case | CPU | Sensor 3 | Core 0 | Core 1 | +3.3 | +5.00 | +12.00 | -12.00 | -5.00 | Fan 1 | Fan 2 | Fan 3 |
+---------------+---------------+----------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+
| 3/21/2006 | 11:02:34 PM | 2006 MHz | 35° C | 49° C | 0° C | 1.65 V | 2.62 V | 3.33 V | 5.05 V | 12.10 V | -12.35 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:02:24 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.33 V | 5.05 V | 12.10 V | -12.27 V | -5.24 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:02:14 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.63 V | 2.62 V | 3.33 V | 5.05 V | 12.10 V | -12.27 V | -5.24 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:02:04 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.34 V | 5.05 V | 12.10 V | -12.27 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:01:54 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.33 V | 5.05 V | 12.10 V | -12.27 V | -5.24 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:01:44 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.33 V | 5.08 V | 12.10 V | -12.35 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:01:34 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.33 V | 5.05 V | 12.10 V | -12.27 V | -5.24 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:01:24 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.31 V | 5.05 V | 12.04 V | -12.35 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:01:14 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.34 V | 5.05 V | 12.10 V | -12.27 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:01:04 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.34 V | 5.05 V | 12.04 V | -12.27 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:00:54 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.63 V | 2.62 V | 3.34 V | 5.05 V | 12.10 V | -12.27 V | -5.24 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:00:44 PM | 2006 MHz | 35° C | 48° C | 0° C | 1.65 V | 2.62 V | 3.34 V | 5.08 V | 12.04 V | -12.35 V | -5.29 V | 0 RPM | 0 RPM | 0 RPM |
| 3/21/2006 | 11:00:34 PM | 2006 MHz | 35° C | 47° C | 0° C | 1.65 V | 2.64 V | 3.33 V | 5.05 V | 12.10 V | -12.35 V | -5.24 V | 0 RPM | 0 RPM | 0 RPM |

 

[BadThad]

First off, make sure all your fans are running and at full speed....especially the CPU fan!

- Look over the mobo closely, especially the capacitors. Abit used a lot of bad caps in the past. Look for crusting or bulging. Bad cap = toast mobo

- Reseat EVERYTHING connected to the mobo...don't just feel if it's tight, pull everything off and put it back on.

- Final measure, get a new power supply....and a good one like a Seasonic or OCZ.

 

[KnickNut3]

Sorry, it's not a COOLMAX... for the life of me I can't find my e-mail confirmation for it... this is one I bought to replace that one. It has a 3 speed adjustable fan... I just upped the fan from medium to high.

Interesting development: I have 2 monitors--one Dell 2001fp LCD, one NEC 19" CRT. The computer has crashed when playing video three times, every time with the video on the LCD at full screen. I've watched about 2 hours of shows on the CRT with NO crashes. I changed the power cable of the LCD to its own separate outlet--maybe displaying video on the LCD is drawing a kind of power that is screwing everything up. Does an LCD use more energy than a CRT (I thought it was less)?

Anyway, FWIW that's the latest development. I'll have to wait a few weeks before I have time to take anything apart. This happened after I took my PC home and back to school, so I hope transit didn't harm it.

Thanks.

 

[BadThad]

LCD uses WAY less power than a CRT. Sure hope your LCD isn't going out!

 

[BadThad]

Oh...next time it happens, leave the PC alone and plug the CRT in to see if it's the PC or the LCD.

 

[KnickNut3]

Well, they're both plugged in at the same time, and the signal goes out on both of them simultaneously (sorry if that wasn't clear originally). They have just happened to crash when the LCD was doing the actual graphics-intesive displays. Not sure if that was just coincidence, but doesn't appear to be so far. I'll try unplugging the LCD next time it happens.

Thanks

 

[Itoq]

Video card overheating? I would try taking the side of the case off and pointing a big fan at it to see if that is the problem. Sounds like problem I had with 6800 before I rma'ed it, although I think that was either PSU or more likely mb chipset incompatability related.

 

[BadThad]

You didn't mention if all your fans are running properly. Also, while your looking, shut it down and reseat everything....don't just feel if it's tight, pull out and put back in.

 

[KnickNut3]

Yeah, all the fans are perfect.

Happened again this morning (first time in a few days) after I watched a small video in my web browser. It just finished and I wasn't doing anything special. Very weird.

I'll try yanking my PC out and reseating stuff today (and figure out my PSU model), but I'd appreciate the other thoughts in the meanwhile.