What happens if Power supply is too weak?

[Kanaljak]

So basically what happens if the Power supply is too weak?
Does the computer just shut down?

 

[harrypot]

not always sometimes it crashes, other times components dont function such as graph cards or they stop working, also it may fail to start at all. also the pc can limit what u do. its always better to have too much power than to little especially on modern pc's and on the 12 rail.

 

[wa1]

It could frying the other components...
Like harry said, better have more power than u needed.

 

[13thmonkey]

often lots of random unconnected stuff, instabilites, smoke, small flames, game failures....

 

[jamesgoddard]

a low quality PSU would = boooom!!!