PSU issue???

[Rokkaholik]

I'm currently working on restoring a Pentium D computer for someone. The tower seems to shut down on its own, but yet the power light stays lit on the front panel. Hibernation is OFF, and the monitor settings are where they're supposed to be. Windows installed fine and the first batch of MS updates installed fine, so I was wondering if they had a problem or not. All the hardware tests fine (memory, roms, hdd, etc). THEN it finally started shutting down on me randomly whether I was doing updates or just sitting idle. The thing that's throwing me off is the power light staying on.

 

Is there a possibility that one of the parts in the PSU that controls either the 4 pin mobo power or the 24 pin is somehow going out? Or could it possibly be either the north or south bridge on the motherboard?

 

I did have a spare 24 pin PSU from a friends HP I upgraded, so that's in there now and I left the PC running to see what it does.

Edited July 21, 2010 by Rokkaholik

[sack_patrol]

I'm currently working on restoring a Pentium D computer for someone. The tower seems to shut down on its own, but yet the power light stays lit on the front panel. Hibernation is OFF, and the monitor settings are where they're supposed to be. Windows installed fine and the first batch of MS updates installed fine, so I was wondering if they had a problem or not. All the hardware tests fine (memory, roms, hdd, etc). THEN it finally started shutting down on me randomly whether I was doing updates or just sitting idle. The thing that's throwing me off is the power light staying on.

 

Is there a possibility that one of the parts in the PSU that controls either the 4 pin mobo power or the 24 pin is somehow going out?

 

I did have a spare 24 pin PSU from a friends HP I upgraded, so that's in there now and I left the PC running to see what it does.

Could it be that the PSU isn't powerful enough to handle the hardware, rather than it being defective?

[Rokkaholik]

It's the stock one that came in the computer when it was new. It's one of the generic types like Hercules, Bestec or something like that. I'm not sure of the wattage, but I think it's 425w

[sack_patrol]

It's the stock one that came in the computer when it was new. It's one of the generic types like Hercules, Bestec or something like that. I'm not sure of the wattage, but I think it's 425w

well, if it came with the PC as it is, then it's supposed to be able to handle the hardware. In this case, it's probably starting to die. Instead of putting a new PSU in this PC, put the current supposedly faulty PSU in another PC and see if it fails.

[Rokkaholik]

Thats the hard part... It's random when it does it. Sometimes it's 2-3 times in 5 minutes, and other times the PC stays running for over an hour. It doesn't matter if it's idle or actually doing something. The spare PSU has been in the PC for about 4 hours now with no issues thus far. I'm starting to lean towards something in the PSU is going out. It's not clicking or making any noises and checking the front and back vents, it's not overheating either. I figure it has to be a bad cap, transformer, rail, or something in the PSU that's causing it. The fact that the power light stays on, but yet everything else shuts off makes me think its in a specific power cord (4 pin or 24 pin)

[sack_patrol]

Thats the hard part... It's random when it does it. Sometimes it's 2-3 times in 5 minutes, and other times the PC stays running for over an hour. It doesn't matter if it's idle or actually doing something. The spare PSU has been in the PC for about 4 hours now with no issues thus far. I'm starting to lean towards something in the PSU is going out. It's not clicking or making any noises and checking the front and back vents, it's not overheating either. I figure it has to be a bad cap, transformer, rail, or something in the PSU that's causing it. The fact that the power light stays on, but yet everything else shuts off makes me think its in a specific power cord (4 pin or 24 pin)

In that case I'd check the 24pin first.

 

Could you try running both PSUs but using the faulty one for everything else but the 24pin, and the good PSU on the 24pin. Then leave it working until it fails or until it doesn't for quite some time, and then (if you feel like doing all this) reverse the 2 PSUs by putting the faulty for the 24pin and the good for everything else and seeing how it goes. (i dunno...just random ideas that seem good in my head xD)

Edited July 21, 2010 by ballist1x

[Rokkaholik]

It's a $10-15 PSU at most so I'm not too worried if it is. I was just confused by the power light staying on, on the front of the case.

[sack_patrol]

It's a $10-15 PSU at most so I'm not too worried if it is. I was just confused by the power light staying on, on the front of the case.

Ah I see. Well it's not such a big loss then.

 

My ancient PC has one of those 450w PSUs that you can also plug the monitor in it. Too bad they don't make those anymore... I don't think it's practical since more energy is wasted when you could just plug the monitor in the wall. The only use for this would be if you are taking everything from the USA to europe or vice versa, and instead of buying all these converters, all you do is switch the little button on the PSU for the voltage and everything'll work since it's all connected to it.