Originally Posted by jeremygj
Wouldn't it be a bad idea to go into a psu? really easy way to be on your back with smoke coming off of you.
Not if you are careful. As long as it's been unplugged for 30 mins or so, most of the caps would have discharged, and even if charged, would only give you a small zap. You'd feel it, but i doubt it would kill you. Plugged in is a different story, where it can supply a continuous current. Its really only the primary side that is dangerous, the most you'll get on the secondary side is 24V (between the +12V and -12V). On the primary side, its a different story, in 240V areas like the UK, you can get up to 339V , and some of that stored in the large filter cap. I suspect this is the one that blew out though. Most PSU's nowadays have paths for the voltage to dissipate after a few mins though, and rarely hold a charge for a long time. Common practice is to discharge the high-voltage caps through a resistor - a 1K 1Watt resistor on probes would do to discharge and caps. Or just check with a voltmeter to make sure its discharged - the voltmeter internal resistance would discharge the cap too. :-)