about a year ago my dell desktop pc wasn't turning on. the power button kept blinking orange. so I thought maybe something was loose or switched off. I looked at the back of the psu and saw a red switch. thinking it was the on/off switch, I slided it to the other side and instantly the computer went 'BANG' with a zapping noise. I instantly turned every thing off and the pc has been in a storeroom since. I later found that I had changed the psu voltage switch from 240 volts to 115 volts
now my question is that would it be safe to plug in this pc to the mains just for testing. I know 99% it will probably not work but do you think its safe interms of electrocution or further damage or bangs.
Best Answer
No, don't plug it in. The "bang" was a component getting destroyed. Hopefully a fuse, but likely something else.
The danger (other than getting shocked or starting a fire) is that the PSU's output voltages may no longer be correct. This could destroy your motherboard (bad) or hard drives (worse, in my opinion).
Of course, this may have already happened...
If you have data on your hard drive that you want to recover, I recommend buying a "usb hard drive bay" (or "usb hard drive docking station") (~$15USD) and using another computer to access the data. These bays provide a level of isolation between a possibly-bad hard drive and the computer.
You could simply connect the hard drive directly to a different computer, but this risks damaging the new computer's power supply if the hard drive has developed a short circuit...
After you save your data (or not, if you don't want to), you can simply replace the power supply and see what happens :)