i've had dozens of pc power supplies, mostly cheap and a few expensive, go out on me in spectacular and not-so-spectacular ways...while running or even just plugged in and powered off (+5v standby actually blew up 2 units). this most recent failure is a new one on me though. i installed an old 350w just pc inc. model jpc-350-12v in an athlon xp system with a radeon 9800 non-pro. a cheap build, but with good 5v (35a) and 3.3v (28a) stats for a pentium 4 psu plus it had 50% more weight than the previous ultra-cheap 500w psu that blew.
the new power supply operated for maybe 12hrs non-continuous before shutting off unexpectedly. i can reset the psu and power the system back on, but it only runs a few sec before shutting itself off again. if i let the system rest awhile, it will run longer and even clear post before powering off and repeating the same cycle. i recall having another power supply exhibit the same behavior when its cooling fan failed, but there's nothing wrong with the fan here. in any case i swapped out the bad psu and the system operates fine now. i ran it under load for 30min just to be sure.
was it the motherboard or the psu itself shutting off? what kind of protection circuits, if any, came into play here? my (considerable) experience is that cheap power supplies, being cheap, just blow up. i don't think many have any kind of thermal protection at all. i have opened up a number of them to salvage the cooling fans and notice the fuses haven't blown even after catastrophic failure (small fires, exploded capacitors, other components rattling around). just curious why only this failure, out of dozens cheap or expensive, was so controlled.
the new power supply operated for maybe 12hrs non-continuous before shutting off unexpectedly. i can reset the psu and power the system back on, but it only runs a few sec before shutting itself off again. if i let the system rest awhile, it will run longer and even clear post before powering off and repeating the same cycle. i recall having another power supply exhibit the same behavior when its cooling fan failed, but there's nothing wrong with the fan here. in any case i swapped out the bad psu and the system operates fine now. i ran it under load for 30min just to be sure.
was it the motherboard or the psu itself shutting off? what kind of protection circuits, if any, came into play here? my (considerable) experience is that cheap power supplies, being cheap, just blow up. i don't think many have any kind of thermal protection at all. i have opened up a number of them to salvage the cooling fans and notice the fuses haven't blown even after catastrophic failure (small fires, exploded capacitors, other components rattling around). just curious why only this failure, out of dozens cheap or expensive, was so controlled.
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