How long can a capacitor hold it's charge?

[Forest_Penguin]

I am planning to do some maintenance on my macintosh se but I'm worried about taking out the power supply. The PSU is completely exposed and I need to take it out. Having heard that opening up a PSU can potentially kill you I am a bit worried. Some people have told me a capacitor can hold it's charge for a few hours and others a few months. What should I do?

Are there parts of the PCB that are safe to touch?

Will turning the computer on while unplugged drain the capacitors?

Is there a way to make sure that the capacitors are uncharged? (I don't own any sort of special tools for something like this)

The computer hasn't been turned of for atleast 3-4 weeks now.

 

[turkey3_scratch]

I think you mean hold it's energy, as the net amount of charge is the same in a charged and discharged capacitor (I know it can sound confusing). Well, some capacitors have bleed resistors connected on the circuit and what the bleed resistors do is "discharges" (de-energizes) them over time. Other than that I don't have specifics for you in terms of time. Somebody else may be able to provide that input.

 

[boosted1g]

Best thing you could do is get some rubber electricians gloves so that way you wont get shocked.

 

[Kurz]

Pressing the on button with the PSU unplugged from the wall is usually enough.