Motherboard Killing Power Supplies?

[DeathFromBelow]

I recently put together a mini-ITX system with an Intel Q8200, 4 GB RAM, ZOTAC GF9300-D-E, 500 GB 3.5" SATA hard drive and a slim SATA DVD drive.

The 250W power supply that came with the case died after a couple hours of stable use. I figured it was junk and replaced it with a nice SeaSonic SS-300TFX 300W unit. Again, after a few hours of stable use it seems to have met the same fate. I tried plugging in a spare power supply I have here and the system seems to work fine again.

WTH is going on here? Has anyone else seen a motherboard eat power supplies? I assume a nice 300W like that SeaSonic would normally be fine for a 2.3GHz Quad and integrated Nvidia 9300 graphics...

 

[unrlmth]

Nope never seen that before, but it might just be an unusual coincidence. And even if it got shorted out somehow it should just shut off.

 

[Dangman]

Nope, it's the other away around: It's always the PSU killing the mobo. Never the other way AFAIK.

As for what's causing the deaths of two PSUs so far, it could be:
- Bad luck on your part
- An electrical issue in your home
- Shipping damage

Wait, what case did you buy that came with a 250W PSU? If it's one of those Rosewill/Apex/Thermaltake look-alikes, then there's one explanation: The included 250W PSU in those case/PSU combos are of low quality and are more than likely not capable of providing their fully rated wattage. So basically, the power load of the PC would be too much for those 250W PSUs.

As for the 300W Seasonic, random failure or just bad luck.

 

[DeathFromBelow]

Wait, what case did you buy that came with a 250W PSU? If it's one of those Rosewill/Apex/Thermaltake look-alikes, then there's one explanation: The included 250W PSU in those case/PSU combos are of low quality and are more than likely not capable of providing their fully rated wattage. So basically, the power load of the PC would be too much for those 250W PSUs.

Yeah, the power supply that came with the case was a shitty Winsis. I was planning on replacing it anyway.

As for the 300W Seasonic, random failure or just bad luck.

Hmmm, it just seems odd that two power supplies would die in a row after apparently working fine (long enough to run memtest and install/play around in Windows anyway). I'm afraid to hook it up to another new power supply.

House wiring/electricity is fine.

I'm using a slim DVD drive in this case and had to get a molex to slim SATA power cable. Could a short there or somewhere else in the wiring cause this sort of issue?

 

[EvilPokemon]

The odds are very small. However, if a MB is regulating and requesting power improperly it can definitely fry a PSU. Of course at this point that converter sounds like the more likely culprit.