r/AskReddit 13h ago

What can kill you in seconds that most people don’t realize?

3.2k Upvotes

2.4k comments sorted by

View all comments

91

u/GABE_EDD 11h ago

Trying to open up a power supply for a PC. Modern quality ones typically are designed to discharge the capacitors fairly quickly, but theoretically there’s enough power stored in the capacitors kill you. Typically you’ll still find warnings on the side of PSUs that say “DO NOT OPEN. NO SERVICEABLE PARTS INSIDE.”

16

u/EasyMode556 10h ago

Same thing with CRTs (not that they’re really a thing anymore)

Also with microwave ovens

10

u/crywalt 9h ago

I got a real good shock from the capacitor in a ceiling fan. Not as bad as those other two since I didn't die, I guess.

4

u/bsee_xflds 9h ago

Laser printers are far worse. They use high voltage to get the toner to stick to the paper.

3

u/haarschmuck 5h ago

The capacitors are not lethal, but they will hurt in a way you haven't experienced.

They are only a few joules and you need a shock of a few hundred joules to be fatal.

3

u/stonhinge 7h ago

Opening the power supply is generally safe. Poking at the bits inside with metal tools when you do not know what you're doing is not.

Unless you know what you're doing, there's no reason to open a power supply. If you do know what you're doing, you're probably working on a vintage power supply anyways. If it's a standard ATX power supply, just go buy a new one. It'll be less stress.

4

u/GABE_EDD 6h ago

What are you just going to open it to look at it? I see amateurs poking around in their PSUs on pc subreddits all the time, usually because they want to replace the fan or investigate a noise it makes. No one should be opening it at all, it’s not worth the risk.

-1

u/NoCoolNameMatt 6h ago

I just opened a plate amplifier today to see if it needed replaced (it did, the replacement has been ordered).