Help! What are the signs of a bad power supply?

[KarsinTheHutt]

What are the effects of a bad power supply on components? I'm trying to figure out why someone else's system is going haywire. Symptoms include random crashes, sound card errors, video card errors, etc. I think these occur even after fresh OS installs

Sound card - Sound Blaster SB Live!
Video Card - Gillemont 3D Prophet (GeForce256)
Mobo - some sort of BX based board with a P!!!450
Power supply - 300 Watt approved for AMD Athlon
HDD - Western Digital 18 GB 7200 RPM

 

[jinsonxu]

When did the problem start?

 

[GAZZA]

My experience from a bad PS is troublesome booting up, for instance it was almost impossible to boot up correctly , sometimes it did but was very frustrating getting it to boot right.
By chance i had another PS on the way and when i switched it round it booted first time , when i checked out the old Ps i found that the pcb in the PS was black and certainly dying.