PC blowing power supplies

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Martian

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Was on my computer the other day, went out for about 5 minutes and came back to a dead pc. No power, no lights, nothing. As the pc is a little old I thought it might be the psu, tested on another computer and found this to be the problem.

So today I manage to find a replacement psu, connect everything and pc looks to be working fine. About 10 minutes after I switch it on I hear a popping noise, the pc switches off and I smell a burning smell coming from the case. So once again, the psu is screwed.

Any ideas on the cause? I'm not in the mood to blow another psu.
 
First test your mains to see what voltage you are getting
I have seen some 220V supply's as high as 260V and as low as 180v
After that a few things you could try
I would start the motherboard on a piece of wood out side the case with just the power supply best way is with an amp meter in circuit as you add components to see what give you an unusual current draw.
But if you are trying to draw 500W from a 250W PSU :D
Can you post your PC specs and the PSUs that blew
 
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What PSU make/model was/is it (old and new one)? What are your PC specs and age? Was something recently moved that could cause a short?

+1 for removing the mobo and parts from the case and checking - if there is a short in the case, it will probably blow the PSU - any bugs, moths or ants inside your case; been known to play havok with PSU's and components.
 
A few questions:

a) What was your first PSU and how old was it? Was it a 'cheapie' or included with a generic case you bought?
b) What was the replacement PSU?
c) Did you check to make sure that the motherboard is mounted properly and contact with the motherboard tray is not possible (i.e underneath of motherboard is NOT touching tray and thereby conducting/shorting).
 
I'm running an AMD dual-core, 4gb ram, 260gtx. Original psu was a Procase 350w but it lasted a good 3-4 years hence me not being too surprised at its demise. Replacement was a 500w, not sure of the make, could also be Procase.

Didn't add or remove any components to or from the computer prior to the original psu going. Didn't fiddle with anything either.
 
Thanks for the suggestions guys, will let you know if the problem gets resolved.
 
marine1:8036380 said:
Have you opened the PSU and checked if just the fuse is blown? Cheaper than replacing a PSU
Click to expand...

Have not done that, didn't even think of that, this isn't exactly my area of expertise. Thanks for the suggestion
 
marine1:8036422 said:
No worries, happened to me a few times and all it was, was a fuse but not sure why it is happening.
Click to expand...

Just did a few searches on Google and apparently it's quite dangerous opening up the psu. Am I just being paranoid?
 
marine1:8036476 said:
Well do not open it while it is on or connected :d
I opened mine, replaced the fuse - reconnected and it is fine
Click to expand...

Ha ha no I won't open it while it's still connected, just read that some of the components could still be carrying some electricity.

Next question, where can I buy the fuse? I'm in the Fourways area, don't know if that helps at all.
 
Martian said:
Ha ha no I won't open it while it's still connected, just read that some of the components could still be carrying some electricity.

Next question, where can I buy the fuse? I'm in the Fourways area, don't know if that helps at all.
Click to expand...
haha that is true there are some nasty capacitors that stores some power just leave just unplug it
http://images.bit-tech.net/news_images/2008/08/lian-li-launches-the-all-new-maxima-force-psu-s/Lian-Li-Maxima-PSU-Capacitors-s.jpg

So what u want to do is open the psu up (dont touch what is not needed to be touched) and look for the Fuse pull it out with some pliers but there is a chance some psu units have there fuses solder in so u cant just pull it out. after u pull it out there should be some writing on it saying how many AMP fuse it is just take it with u and get the same rating one
 
When a fuse blows you don't normally smell burning. There's more than likely another component fried in the PSU. My 2c.
 
gcb:8036738 said:
When a fuse blows you don't normally smell burning. There's more than likely another component fried in the PSU. My 2c.
Click to expand...

Well if that's the case then I'm screwed, gonna replace the fuse anyway just to be sure.

Here's hoping you're wrong.
 
Ja power supply is f***ed. Still no closer to finding the problem, ugh.

Once again, thanks guys.
 
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