One night my mom was happily using her computer and then properly shut it down. A few hours later, electricity went away for a few hours. Nothing scary about it.
It was late night so she went to bed and in the morning the lights were blinking. Like there were many sudden breaks in power supply. Some problems with electricity network.
When the situation got normalized again, she tryed to switch on the computer and nothing happened! She checked that all cables were properly attached... and they were. But she claims to have heard some noise... and seen some small "lightnings" when she moved the cables.
She thought it's best to unplug the power and wait for technician (it's me
). And wise she was, indeed, but unfortunately too late 
I uncovered the PC and immediately saw some problems with motherboard: a few components were melted! And the surface of the board was darkened here and there. "That's bad, you need a new mobo". But why's that? There must be some problems with power supply so I took it for more detailed examination. I could sense the smell of burned down electrical components..you know... and it didn't took more than a few seconds and... BAM! And lot's of smoke. "You need a new power supply, too".
Okay, I bought new ones and assembled the PC again. Switched power on and? Nothing happens. At that moment I was too busy to make further examinations and I told to bring it to service.
(Okay, this is becoming too long... I'll make it shorter)
What else were broken? Not much. Only hard disk, display adapter, processor, floppy drive and cd-drive.
The only components that survived were the cover and RAM.
What if there were a Scope card inside... ! I think it's time to buy an UPS for myself.
