[Gazza82]

Elderly neighbour (70 years young) recently switched on his PC and nothing. I suspected the power supply so swapped it over with a spare I had. I disconnected all the drives but left all connections to mother board.

Switched on and fans started .... then pop and the replacement PSU died .... smell of burnt electrics from PSU.

Anyone know how I can test whether the mobo is at fault? I can't see any burnt tracks, scorched components, etc. I'm loathed to buy a new PSU incase it blows as well.

Any help would be appreciated

Gazza

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hi and welcome to geeks to go

well the motherboard might be shorting out with the case. i would suggest removing the motherboard compleatly out of the case and lying it down on a peice of cardboard. if the system does then boot up with no problems you then have to determine where the short was happening.

this could mean buying some new standoffs or washers

but if it blows another power supplie i would buy another motherboard

you can infact replace the blown fuse in the power supplie but you have to match up the very same type as in teh same amp rating

hope that helped a little

troppo

[troppo]

hi and welcome to geeks to go

well the motherboard might be shorting out with the case. i would suggest removing the motherboard compleatly out of the case and lying it down on a peice of cardboard. if the system does then boot up with no problems you then have to determine where the short was happening.

this could mean buying some new standoffs or washers

but if it blows another power supplie i would buy another motherboard

you can infact replace the blown fuse in the power supplie but you have to match up the very same type as in teh same amp rating

hope that helped a little

troppo

[Samm]

Hi there

To be honest, I would be very surprised if the motherboard is taking out the PSU (assuming of course that the PSU is compatible with that particular system). Troppo is right about PSUs having internal fuses, however whether the fuses are replaceable depends largely on the quality of the PSU. Many cheap ones do not have fuses which are easily replaced. Whats more, the burning smell you said you experienced doesn't really tie in with just a fuse blowing. If the smell was definately coming from the PSU then it's probably toast. It is also entirely possible in this case that the motherboard will have been damaged as well.

Before you do anything else, I would suggest you inspect the mains cable that was connected to the PSU, especially of you used the original cable when you swapped the PSU. If in doubt, or if the cable has a molded plug on it, then swap the cable for a known good one.

If the cable seems ok, then there may be a problem with your neighbours wall socket or some other part of the ring main. I would suggest to be on the safe side, that the next time you plug the computer in, do it in your own house instead.

If all of this checks out, then I guess it is possible that both PSUs were faulty

One last thing - if you do decide to open the PSU up to check for fuses etc, please be very careful. Even when the PSU is completely disconnected from the mains, it's capacitors can still retain a massive amount of charge.

Let us know how you get on

[Gazza82]

Thanks guys,

I was using a good mains cable and a different one from my neighbour. Also the PC is now at my house so the power supply is good. My neighbour has a mains filter on his line so I think its fine.

I can't see any damage to the motherboard, but I might try and see if it works on the desk as Troppo suggests .. now to find another PSU!

Not being an electrical engineer I don't know how to test everything thoroughly so it's either trial and error (and possible more blown PSUs) or I just tell him to get a new PC. I guess we could try a new PSU and mobo if he's willing to pay.

I've had nothing but trouble with this one ... mainly software problems and all a result of M$ofts wonderful "Genuine Advantage Package" ... the latest was caused by OnSpeed. He had this from his dial-up days, but an update failed, screwed the software and stopped all internet and mail access ... needless to say it no longer exists on that PC.

[Neil Jones]

Check the voltage settings on the back of the PSU. Set to 240/230v if in Europe and 110v if in the USA. Setting this incorrectly, unsurprisingly, kills the PSU with potential to wipe out the rest of the system.

[Gazza82]

First thing I looked at .... not that. Definitely something spiking the PSU.

Had a chat with the owner last night and we are going to get a new PSU and MOBO.

[Samm]

Let us know how you get on

[Gazza82]

Replaced the PSU and mobo and all working. Got the parts off ebay for under £33 so he was extremely happy.


Did notice that the board (K7VM2) quotes 266Mhz for RAM yet the DDR ram installed has 333Mhz sticker. Don't think that's a problem though.


The PSU foxed me at first. The ATX board main connector has 20 pins but the PSU had 24. Then realised a small section with 4 pins unclipped. Must be for a P4 board or something. But worth remembering.


Good that this board was the same type as when it restarted it didn't need any extra work. Reloaded a few drivers, etc but that was all automatic ....


Boy was I relieved!!!


Thanks for all the help guys and gals.

[Samm]

Glad you got it all working ok. Thanks for letting us know