Cause for power supply failure?

What can cause a pc power supply to fail?

I broke my power supply while reconnecting its power (unplug ac cord
then plug it back in) about a month ago, and I think I did it again
today...while I was doing the same thing. I used a power bar/power strip
with no surge protector. Normally I would think that plugging in a power
cord into the wall socket shouldn't terribly endanger my computer, but
now I'm not so sure.

Any idears?

das der die wrote:

> What can cause a pc power supply to fail?
>
> I broke my power supply while reconnecting its power (unplug ac cord
> then plug it back in) about a month ago, and I think I did it again
> today...while I was doing the same thing. I used a power bar/power strip
> with no surge protector. Normally I would think that plugging in a power
> cord into the wall socket shouldn't terribly endanger my computer, but
> now I'm not so sure.

You're not doing anything bad. Maybe the power supply was designed or
built badly.

What brand is it? Better yet, what's its UL or CSA number? The UL
number is in the form of Exxxxxx and is under a funny RU symbol where
the "R" is backward". The CSA number is probably of the form Lxxxxx.
You can usually find the actual manufacturer
from those numbers at www.csa.ca and www.ul.com.

Bad PSUs aren't designed very well to handle turn-on stress. www.JonnyGuru.com
and www.HardOCP.com have info about PSUs, and the latter has a couple
of reviews of budget models, including interior photos to let you see
what good and bad ones look like.

On Mon, 05 Nov 2007 04:15:53 GMT, das der die
<email.user@example.org> wrote:

>What can cause a pc power supply to fail?

Too many things to list, but IMO the most common faults are
in this order:

Bad capacitors
Poor cooling and/or fan failure
Insufficient true capacity per system (generic PSU usually)
Excessive current or heat on chopper transistor(s)



>
>I broke my power supply while reconnecting its power (unplug ac cord
>then plug it back in) about a month ago, and I think I did it again
>today...while I was doing the same thing. I used a power bar/power strip
>with no surge protector. Normally I would think that plugging in a power
>cord into the wall socket shouldn't terribly endanger my computer, but
>now I'm not so sure.
>
>Any idears?


We'd need details of PSU and system but plugging it in would
seem to be the excessive (inrush) current problem, but to
really know you have to diagnose each one at the discrete
component level. If you're buying generics then I suggest a
better brand instead.

I see. Thank you very much.

kony wrote:
> On Mon, 05 Nov 2007 04:15:53 GMT, das der die
> <email.user@example.org> wrote:
>
>> What can cause a pc power supply to fail?
>
> Too many things to list, but IMO the most common faults are
> in this order:
>
> Bad capacitors
> Poor cooling and/or fan failure
> Insufficient true capacity per system (generic PSU usually)
> Excessive current or heat on chopper transistor(s)
>
>
>
>> I broke my power supply while reconnecting its power (unplug ac cord
>> then plug it back in) about a month ago, and I think I did it again
>> today...while I was doing the same thing. I used a power bar/power strip
>> with no surge protector. Normally I would think that plugging in a power
>> cord into the wall socket shouldn't terribly endanger my computer, but
>> now I'm not so sure.
>>
>> Any idears?
>
>
> We'd need details of PSU and system but plugging it in would
> seem to be the excessive (inrush) current problem, but to
> really know you have to diagnose each one at the discrete
> component level. If you're buying generics then I suggest a
> better brand instead.

Thank you for taking your time to reply. I found your information very
useful.

larry moe 'n curly wrote:
> das der die wrote:
>
>> What can cause a pc power supply to fail?
>>
>> I broke my power supply while reconnecting its power (unplug ac cord
>> then plug it back in) about a month ago, and I think I did it again
>> today...while I was doing the same thing. I used a power bar/power strip
>> with no surge protector. Normally I would think that plugging in a power
>> cord into the wall socket shouldn't terribly endanger my computer, but
>> now I'm not so sure.
>
> You're not doing anything bad. Maybe the power supply was designed or
> built badly.
>
> What brand is it? Better yet, what's its UL or CSA number? The UL
> number is in the form of Exxxxxx and is under a funny RU symbol where
> the "R" is backward". The CSA number is probably of the form Lxxxxx.
> You can usually find the actual manufacturer
> from those numbers at www.csa.ca and www.ul.com.
>
> Bad PSUs aren't designed very well to handle turn-on stress. www.JonnyGuru.com
> and www.HardOCP.com have info about PSUs, and the latter has a couple
> of reviews of budget models, including interior photos to let you see
> what good and bad ones look like.
>