Completely dead PC? Or just PSU?

ixoy

Everything was fine with my PC last night but, when I went to turn it on this morning, I got nothing. No response, not even a beep.

I tried a different socket and a different plug as well - no change. I opened it up and noticed that, when switched "on", the light on the motherboard (Abit KN8 SLI) that should indicate when the power supply is connected to a power source, was not lit. There was also no vibration anywhere within the machine - no sound of anything whirring, or any power getting through whatsoever.

Does this sound like a PSU issue? Is there any way of being sure short of trying a different power supply? I'm guessing using a voltmeter of some sort?

Follow-up question: How difficult is it to install a different PSU if this is the issue? This one came with the case (an Antec Sonta II - it's a 450W PSU). Are PSUs specific to particular cases or can I lob any old one in of comparable wattage?

CHW

ixoy wrote: »

Everything was fine with my PC last night but, when I went to turn it on this morning, I got nothing. No response, not even a beep.

I tried a different socket and a different plug as well - no change. I opened it up and noticed that, when switched "on", the light on the motherboard (Abit KN8 SLI) that should indicate when the power supply is connected to a power source, was not lit. There was also no vibration anywhere within the machine - no sound of anything whirring, or any power getting through whatsoever.

Does this sound like a PSU issue? Is there any way of being sure short of trying a different power supply? I'm guessing using a voltmeter of some sort?

Follow-up question: How difficult is it to install a different PSU if this is the issue? This one came with the case (an Antec Sonta II - it's a 450W PSU). Are PSUs specific to particular cases or can I lob any old one in of comparable wattage?

Sounds like the PSU. On most PSUs if you take it out of the PC, and short pins 14 and 15 with a paperclip, the fan should come on (connecting the 2 pins is like pressing the power button on your PC). Some info here http://www.duxcw.com/faq/ps/ps4.htm If the fan doesn't come on, then likely something inside the PSU is kaput. Some PSUs have a fuse inside, so the issue could be here.

Should be a simple swap with comparable PSU to fix things, provided the problem is with your current PSU.

Adder1

ixoy wrote: »

Everything was fine with my PC last night but, when I went to turn it on this morning, I got nothing. No response, not even a beep.

I tried a different socket and a different plug as well - no change. I opened it up and noticed that, when switched "on", the light on the motherboard (Abit KN8 SLI) that should indicate when the power supply is connected to a power source, was not lit. There was also no vibration anywhere within the machine - no sound of anything whirring, or any power getting through whatsoever.

Does this sound like a PSU issue? Is there any way of being sure short of trying a different power supply? I'm guessing using a voltmeter of some sort?

Follow-up question: How difficult is it to install a different PSU if this is the issue? This one came with the case (an Antec Sonta II - it's a 450W PSU). Are PSUs specific to particular cases or can I lob any old one in of comparable wattage?

yes it looks like the power supply now I know this sounds obovious but firist check that the fuse in both plug tops is not blown . Also check that the power supply switch didn`t get switched off by accident (this happened to me once ) also check power lead with phase tester to see if power is getting this far. It is a fairly simple matter of unscrewing a few screws removing the power supply fitting new one replacing screws then simply plug in the power connectors to the board ,hardrives,dvd drives,graphics cards ect. If the leads on your old supply are long enough leave them plugged in the replace them one by one with the new supply once you have it mounted makes it easier to see what plugs go where. before getting a new supply check what connectors you need (by looking at the old ones or you motherboard manual also check the wattage needed go for a higher rated one if possible as this will not have to work as hard an so be quiter and last longer will also allow for additional devices to be added to the computer finaly go for a brand model as some cheaper ones are not good and it is possible they could damage the mother board

ixoy

Thanks for the replies - I've tried a mixture of cables and sockets with it, each producing no different different result (and working with other devices), so I feel I can safely rule out that. Additionally, the Sonata II PSU that I'm using has reported defects with the PSU - Antec spokesman even admitting as much - so maybe I'm just another victim.

Looks like I'll need to test the PSU itself - is there any point in trying a voltmeter with the mainboard to see if its being supplied with energy? Or is better to go through testing the PSU directly?

Also are most PSUs the same - so I could swap in another 450W/500W PSU? What sort of details would I need to look out for - most seem to have 24 pin, +12v/5v as standard... are there other things to note?

CHW

ixoy wrote: »

Thanks for the replies - I've tried a mixture of cables and sockets with it, each producing no different different result (and working with other devices), so I feel I can safely rule out that. Additionally, the Sonata II PSU that I'm using has reported defects with the PSU - Antec spokesman even admitting as much - so maybe I'm just another victim.

Looks like I'll need to test the PSU itself - is there any point in trying a voltmeter with the mainboard to see if its being supplied with energy? Or is better to go through testing the PSU directly?

Also are most PSUs the same - so I could swap in another 450W/500W PSU? What sort of details would I need to look out for - most seem to have 24 pin, +12v/5v as standard... are there other things to note?

Yes, if there are reported defects, then you're probably just another unlucky one! Is it still under warranty?

No harm testing the PSU voltages if you have the equipment and know-how - I wouldn't bother testing on the mobo though, just use the picture in the link I gave above as a reference. To see the voltages, you will need to short 14 and 15 on a 20-pin supply (SHOULD BE GREEN AND BLACK - might be 15 and 16 on a 24-pin power connector http://en.wikipedia.org/wiki/Computer_power_supply) together to simulate power switch on. I think that the LED on the mobo not lighting is a sign that the PSU is probably kaput though, but worth testing it anyway to rule it out.

Nearly any equivalent PSU will be fine as a replacement as far as fitting your case and voltages are concerned. Just make sure it has the same connections you'll need, for mainboard, processor (might be 4 or 8 pins, depending on your board), hard drive(s) (molex or SATA), floppy if you still use one.

ixoy

Yep, PSU is as dead as our economic prospects.

Looking at new ones and I can see that my MB needs a 24-pin ATX cable, a 4-pin (in a square formation) ATX12 for the CPU and a number of SATA connections (5). The PCI Express card seems to be powered just off the mainboard.

Looking around at Komplett, it seems this Corsair 450W model would work. Couple of things:

1) "power 8 pin EPS12V with detachable 4 pin ATX12V section" - I'm assuming the detachable 4-pin is in the same "block" formation as my own ATX12V.

2) There's a number of Molex connections on the MB yet none of the advertised PSUs mention Molex connections - only SATA. How do I get around this?

3) Any point to going to a higher wattage this time around? I don't have too much attached - 2 SATA hard drives, 2 DVD drives, and one PCI graphics card.

the_syco

ixoy wrote: »

Looking at new ones and I can see that my MB needs a 24-pin ATX cable, a 4-pin (in a square formation) ATX12 for the CPU and a number of SATA connections (5). The PCI Express card seems to be powered just off the mainboard.

4 pin CPU are standard, as are the 24 pin ATX connection.

ixoy wrote: »

Looking around at Komplett, it seems this Corsair 450W model would work.

Should do.

ixoy wrote: »

1) "power 8 pin EPS12V with detachable 4 pin ATX12V section" - I'm assuming the detachable 4-pin is in the same "block" formation as my own ATX12V.

Aye. Some of the newer mobo's, like mine, has a 8 pin connection next to the CPU.

ixoy wrote: »

2) There's a number of Molex connections on the MB yet none of the advertised PSUs mention Molex connections - only SATA. How do I get around this?

Presume the bit where it says "8 x 4 PIN internal power" means molex. All else fails, there are SATA-Molex connectors, for €2.50 each.

ixoy wrote: »

3) Any point to going to a higher wattage this time around? I don't have too much attached - 2 SATA hard drives, 2 DVD drives, and one PCI graphics card.

Not really. If you have an AGP port, or maybe a PCI-E port, think of getting a 600W PSU, as you know you'll upgrade eventually...