Opening a PSU (safety)

Superbia

Superbia

Superbia

Associate
Joined
28 Jun 2011
Posts
23
Hi all, I’m putting together a display of old PC parts I’ve bought online, and purchased an old PSU, basically mounting everything on a peg board so the students can see it.
The PSU is quite heavy so to reduce weight and for students to see inside i thought about taking the top off is that safe?

I read online about capacitors holding charge, it’s been sat with me for about a week and god knows how long prior, is it ok to take the top off and mount it to a peg board or should I leave it as a sealed unit.

Bit worried a kid will stick their fingers in it.
 
Superbia said:
I read online about capacitors holding charge, it’s been sat with me for about a week and god knows how long prior, is it ok to take the top off and mount it to a peg board or should I leave it as a sealed unit.
Click to expand...

I would be AMAZED if a PSU capacitor held charge for longer than this. Generally they will lose charge much quicker. It’s not like a CRT monitor. After a week it’s almost certainly safe.

Best bet is to try and discharge it anyway.

I open PSU’s all the time, but I do tend to let them sit about for a few days. I wouldn’t open one straight after use for example.
 
rare said:
I would be AMAZED if a PSU capacitor held charge for longer than this. Generally they will lose charge much quicker. It’s not like a CRT monitor. After a week it’s almost certainly safe.

Best bet is to try and discharge it anyway.

I open PSU’s all the time, but I do tend to let them sit about for a few days. I wouldn’t open one straight after use for example.
Click to expand...

I opened up a mini UPS I've got due to a problem with it - the mains side capacitors were still at potentially lethal voltage levels (60+ volts) after several days! though whether they'd be able to overcome skin resistance, etc. and actually deliver a dangerous shock I'm not going to test :s (Took about 2 weeks before they were no longer registering a voltage on my DMM).

Some types of capacitor, less likely in a PSU though not unheard of, can potentially store a high level of charge for months.
 
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I would think a UPS may be more susceptible to it just because of the nature of its design? But I would be really surprised if a modern PSU kept any meaningful charge after a week, heck even after a day.

Best bet is to try and discharge it beforehand anyhow obviously.


www.overclock.net

Capacitor Safety In Power Supplies

We've all heard it at least once. "Dude, don't open up that power supply, the capacitors will shock you and you'll die! You have to unplug it, flip its switch twenty times, leave it out overnight, then you can open it up; but don't forget to wear rubber gloves and to say the special...
www.overclock.net www.overclock.net
 
Thank you for the replies all, it’s put my mind to rest, I’ve left it to one side for now as planning to glue / cable tie the parts next week, I think the most fun part has been seeing my wife’s reaction when a bunch of parts came through the post, had to prove they only cost a couple of quid.

Thanks again.
 
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