Desktop PC: Knowing whether the issue is the motherboard or power supply

angelavdavis

Hi,

I have a Pentium 4 desktop, which I have had now for 6-7 years. I bought it as a home PC which I could expand in order for it to be usable for a good time - it has been a good PC, during its life it has had RAM upgrades, a couple of card expansions (USB2 and network cards), a replacement power supply (after a bad storm here - since purchased a surge protector) and a DVD writer upgrade.

It has done well all in all, but I recently replaced the HDD after a failure, rebuilt it with XP and steadily reloaded my software back on it. It appeared happy, but the other day when I went to switch it on, nothing - dead. It had previously been powered down correctly, so it was clearly a fault.

I am unsure if the power supply has gone again (its a Tsunami 350w) or whether the motherboard has finally died.

I have checked the connections inside in case I had inadvertedly dislodged one during the HDD replacement, but they seem secure. But before I invest in another power supply, only to find its the motherboard, any thoughts on how I can determine if it is the power supply - other than buying another one?

Any ideas?

fwor

First thing to try would be to swap the mains cable for one that you know works, just in case the fuse in the plug has failed.

Next would be to check the power switch as very occasionally they can pop off the back of the front panel.

If it's still completely dead then it's almost certainly a failed PSU. I know this a bit of a generalisation, but most types of motherboard failure should not stop it powering up (though many will mean that it won't get through POST).

If you want a further test, a Wanted ad on Freecycle for an unused PC tower will often yield useful bits, though you need to be sure to get the right part, and that it was working when last used!

isofa

See if the PSU powers up a hard drive or not.

angelavdavis

fwor wrote: »

First thing to try would be to swap the mains cable for one that you know works, just in case the fuse in the plug has failed.

Next would be to check the power switch as very occasionally they can pop off the back of the front panel.

If it's still completely dead then it's almost certainly a failed PSU. I know this a bit of a generalisation, but most types of motherboard failure should not stop it powering up (though many will mean that it won't get through POST).

If you want a further test, a Wanted ad on Freecycle for an unused PC tower will often yield useful bits, though you need to be sure to get the right part, and that it was working when last used!

Thanks, had checked the cable (sorry forgot to say).

I should have thought of freecycle - am pretty good at remembering it when I need to get rid of stuff but rarely use it as a requester!

I had a weak moment and bought another PSU on ebay (£16 so not huge sum). I figured after 7 years without issue another £16 on top of the £45 HDD replacement cost was worth a go.

Regeneration

you could use this method to test it if you still want to
http://www.techwarelabs.com/guides/misc_mod/psumod/

DatabaseError

psu is the most likely, I think i've had 1 motherboard go on me in 15 years of building / playing with PCs.
Personally I wouldn't spend less than £40 on a PSU, the one in my machine was around £80, but I expect it to last forever and to be rock solid

angelavdavis

OK, fitted the replacement PSU today, and nothing!

Have tried different power cables, including one I unplugged from a printer, but still nothing. No lights....system sounds....fan...life!

Checked the actual cable connections going into HDD, FDD, DVD, motherboard - all appear to be OK.



Any other ideas? Thanks

angelavdavis

tonyhague wrote: »

psu is the most likely, I think i've had 1 motherboard go on me in 15 years of building / playing with PCs.
Personally I wouldn't spend less than £40 on a PSU, the one in my machine was around £80, but I expect it to last forever and to be rock solid

Thanks Tony, I know where you are coming from and don't usually stint on paying out for stuff (the PC cost me £3500 when it was new when I could have bought a £1500 model - just because I wanted something that was top of the range at the time but could also be extended and extended as necessary). Remember this is an old model PC (LC-B350ATX PSU), I struggled to find anything over £20 to buy!!!

Fifer

Disconnect all the PSU cables from drives, the motherboard and anything else, then see if it powers up.

XDA

Check the motherboard for an orange light - This will tell you if there's power getting to the motherboard. No light then no power.

angelavdavis

Ended up going to Maplins tonight (nice evening for a drive!) and bought a new PSU. It's working fine now!

Thanks everyone for your help.

Am off to get a refund through Paypal for the other one.....