Is It Dead Jim?

x1m · Post by **x1m** » Mon Feb 07, 2005 11:34 am

I think my psu is dead. Not sure though. So, you tell me.

Came home from work the other day, and monitor wouldn't wake. Rebooted. Wouldn't load windows. Then hard drives started squeaking. Yes. Squeaking. Like three squeaks in a row, then repeat. After that, wouldn't detect ide drives. And its not my ide drive thats a problem, because the sata one doesn't work either. After that, I was lucky if it got to detecting the drives, because it went into a continuous reboot loop. Unplugged everything, and managed to get into the bios long enough to see my +5v was at 4.4v (4.4 != 5

). Now it might be the motherboard, but I'm fairly sure its the psu that's dead( I don't think the hard drives were getting enough power, hence the squeaking). So what do you expects think?

Half of me wants you to tell me its alive, so I'm not without a pc, and the other half wants it dead so I have an exscuse to buy a phantom :] However, I have silence at the moment, the psu is definatly DEAD quiet (ba da boom tisch).

sthayashi · Post by **sthayashi** » Mon Feb 07, 2005 1:32 pm

Get (i.e Buy, borrow, or steal) a multimeter and read the voltage coming from PSU itself. The symptoms sound like a dead PSU, but you never know... It could end up being a really bizarre motherboard problem.

x1m · Post by **x1m** » Mon Feb 07, 2005 1:58 pm

Just a quick question, is the voltage shown in the bios before or after component draw? If it's after, would a multimeter actually give me the correct reading? I should really know this, but brain isn't co-operating.

sthayashi · Post by **sthayashi** » Mon Feb 07, 2005 2:19 pm

I have no idea on the BIOS, but that's why on-board sensor voltage readings aren't always to be trusted. A multimeter will tell you whether or not you're getting 12V/5V from your power supply.

teejay · Post by **teejay** » Mon Feb 07, 2005 2:20 pm

After, but the main issue with mobo voltage readings is that they can be off... way off. Someone recently reported 16V+ on the 12V line. A multimeter gives you a much more accurate idea of what is going on with your psu. The whole idea is that the psu keeps the voltages at the required levels regardless of the current draw. There will always be a little sag but it should be minimal so with or without component draw, the voltages should be at or near the expected levels.

A word of warning: I would disconnect your hdd's while fiddling with this unit... I once killed two disks while experimenting with a faulty power supply unit. If you don't have a spare unit to test with (or a friend you could borrow one from) you can always buy the cheapest unit you can find (around here that's a 400W Q-tec for 15 euros) to use for testing purposes. Always handy to have around in your PC toolbox

ChucuSCAD · Post by **ChucuSCAD** » Mon Feb 07, 2005 4:06 pm

First step in figuring out the problem is to unplug EVERYTHING from the mobo but 1 stick of ram, the cpu and its fan, and video card(only if you dont have onboard to use).
See if that fires up.
If that doesnt work you have one of 5 parts that might be bad. At this point I would borrow a friends system to AB the components out, IE try your CPU in a known working system. Through this process you can find the bad piece.
If it does fire up in the above mentioned situation add in items one at a time till it stops powering up.

In all honesty it DOES NOT sound like a faulty supply. Typically when a supply dies it dies. It does not "fizzle out". My money would be on your hard drives or opticals actually, seen it a million times in my former life when a drive cooked would cause the odd problems you are describing.

chucuSCAD

x1m · Post by **x1m** » Tue Feb 08, 2005 4:35 am

OK, So I'll test it one by one. Thing is, previously I used to get 4.98V on the 5v in bios, and its dropped to 4.4 now. Whether this is because of something else or not I don't know. I'll have to wait until this evening to do it though. Hope its not the motherboard :/

P.S. Former life? Been reincarnated recently? :p

x1m · Post by **x1m** » Tue Feb 15, 2005 12:00 pm

A busy week later and finally found some time to update. I've taken the drives out, and tested them with my brothers pc. No issues whatsoever. Then went to maplins, bought a cheap multimeter. Plugged it in, set it to 20v dc range, and turned psu on. Got about half a second of power, then wham. It goes. AND WON'T TURN ON AGAIN! Naturally I've tested the fuse on the plug etc

Now when the psu is plugged in, the light on the mobo is on, showing it has power. However, hit the power switch, and nothing happens. I tested the power switch with the multimeter, and it still works. Just the motherboard won't have any of it. I ordered a cheap q-tec psu for 15 squid, and hopefully that should arrive tomorrow so I can test with that. Any ideas in the mean time? Is that the sudden lack of working you were expecting? Seems strange though, the light on the motherboard still works. Can i hotwire the psu, so I can turn it on without a motherboard?

Qwertyiopisme · Post by **Qwertyiopisme** » Tue Feb 15, 2005 12:11 pm

Connect green to ground with something like a paperclip. Som eolder PSU's need load on at least one rail (otherwise they turn off) so plug a fan or something in.

ChucuSCAD · Post by **ChucuSCAD** » Tue Feb 15, 2005 4:11 pm

x1m wrote:Thing is, previously I used to get 4.98V on the 5v in bios, and its dropped to 4.4 now.

Not really that strange, all powersupplies arn't exactly the same.

x1m wrote: P.S. Former life? Been reincarnated recently? :p

Before I made the mistake of becoming an architect I was a computer tech.

x1m wrote:I've taken the drives out, and tested them with my brothers pc. No issues whatsoever.

You tested the hard drives in another computer? Or? Have you tried taking everything off the motherboard but a stick of ram, the PSU/sink/fan, and a videocard? no keyboard no mouse.

chucuSCAD