computer just blew

ixoy

Originally posted by COL_LOKI
lol , have a mate who tried that. He got a new PC and was really happy with it, tried to print something for the first time (bout 2 weeks after he got it) and it was really slow ....... naturally he thought the PC was the problem and looked at the back and saw the magic switch...

Thought to himself well what else could it be only fast/slow switch...... few mins later smoke everywhere lol, nearly cried when he told me that story. Supprising how many people do it eh?

Yes, surprising. Suppose I happened to do that recently to my PIII... Would I just have to get a new power supply or is it entirely screwed? Just saying hypothetically - not that I did it or anything :dunno:

Capt'n Midnight

Originally posted by tinky
Switched mode PSU's used in PC's have protection called crowbar. If the 5V rail rises above a preset level a thyristor switches on placing a direct short across the line instantly shutting it down. Also these types of PSU dont vary in output voltage when the input voltage varies they use a reference by which the output is controlled. Switching the psu to 110vac would more than likely just have destroyed the rectifiers and resevoir capacitor instantly blowing the internal fuse - if present - or the plugtop fuse which should be a 3A rating.

Tinky

Even so if you can get a new PSU with a garantee for €30 - it's a better buy than getting the PSU repaired for the same price (despite the minimum wage it would be difficult to get it repaired for that price). The switch usually changes the electrolytics from series to parallel - You would need to change the diodes and Electrolytics at a minimum, but since the capacitance would be four times it's normal value the inrush current may also be that too. If the electrolytics have burst or bulged they might have cracked or stressed the pcb (circuit board). If there is any smell of burning or any damage to other sections of the PSU then ...

Note: Switched Mode PSU's have the highest kill rate of technicians of any electronic circuit (They are LEATHAL - it looks dead 0 Volts and then BAMB !) , also if faulty the voltages can ramp up and of course when working correctly they can have over 330 Volts stored in the for a while after the mains is disconnected. - Nasty evil bastárds

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Though unlike lightening damage the rest of the PC should be ok.

ZENER

Even so if you can get a new PSU with a garantee for €30 - it's a better buy than getting the PSU repaired for the same price (despite the minimum wage it would be difficult to get it repaired for that price).

I never even bother trying to repair them anymore - it's simply not economical to repair them when they only cost about 24 euro trade.

Note: Switched Mode PSU's have the highest kill rate of technicians of any electronic circuit (They are LEATHAL - it looks dead 0 Volts and then BAMB !) , also if faulty the voltages can ramp up and of course when working correctly they can have over 330 Volts stored in the for a while after the mains is disconnected. - Nasty evil bastárds

OOOH the devils own they are, them and TV tubes !! Definetly no user servicable parts in those f**ckers !!! They can sneak up on you just when you think you are invincible !

Tinky