Can a PSU blow twice?

[osmany]

Today a neighbor called me to set up a new computer she bought, but she did not tell me she had already damaged the PSU by plugging the PC to the 220V main, without first changing the power selector switch from 115V to 230V. She only told me she needed to plug the PC to 220V because she did not have a step-down transformer. Then I changed the power supply switch from 115V to 220V and when I plugged the PC to the 220V main the PSU exploded (blown, dead!!!).
Later on my neighbor confessed she had plugged it to the 220V before, without changing the switch for using 220V and it had made the same explosion.

My questions are:
1. Why did the power supply blow again, if it was already dead and also considering this time it was set to use the correct voltage?
2. May have this as well caused damage to the motherboard and or the CPU?
Thank you very much in advance,
Osmany

 

[kimsland]

1.
Yes it blew the first time - dead
Yes power supplies still hold charge - even after pronounced dead !
I wouldn't plug any of my dead power supplies back in either, who knows there may be bits of metal in there, floating about.

In other words Yes it can blow twice

2.
I don't think this has caused damage to M/b and or CPU
But, yes it can (unlikely) but mainly to the M/b and in that to the USBs (they always seem to be the first thing that goes.

In other words No (but you need to confirm with a new PSU at correct voltage!)