What can cause power supply to fail

Practically anything.

That is a pretty vague answer. Unfortunately, it's a pretty vague question.

^+1

Age, Power Surge, Overload, Overheating, Poor Components, If you tip water on it..

Made in China  

Like my Corsair!

I loled but true...


Not all china ware products are bad..

They just need to have a higher quality control.

Most everything computer wise is made in China because of low labor costs. Even the big Taiwanese manufacturers have moved some of their factories to mainland China.

Most power supplies fail due to electrolytic capacitors going high in ESR you can often tell (but not always) which ones these are because of bulging of the capacitors top. The next most common failure is the fan in the power supply becoming noisy or failing to spin, if the fan fails to spin this can cause the destruction of the output rectifiers or the switching transistors. The next most common cause of power supply failure is a catastrophic failure of the switching transistors which can cause the destruction of several more components and also damage the board. Other faults could be the start up resistor going high in value the opto-isolator failing the surge suppressors going short circuit etc

It is important to have a good air flow through the power supply to prevent the above faults from occurring.