Computer all of a sudden fails to power up at all.

[hawkeyewx]

On Saturday night my Mom's computer shut down fine. When she pushed the power button Sunday morning nothing powered up, including the fans. The system, a Duron 800, has been running flawlessly for two years. I tried a different power supply with no success. I tested the power cord and the wall power socket. I tried swapping the motherboard with another, but I got a strange result. I removed the Duron mobo and installed it in my old Celeron case and that system would not power up. That alone would lead me to believe the Duron mobo had a major death somehow(although I don't know how it could die overnight when it wasn't even on). However, I then installed the Celeron cpu/mobo in the Duron case and it also would not power up at all. That part doesn't make any sense. I know for a fact the Celeron system works. Does anyone have any clue what is going on? Why would swapping mobos cause both systems to not power up? I swapped the mobos back into their original cases and once again the Celeron system works fine while the Duron system fails to power up. I don't even know what could cause a system to completely fail to power up. I've had plenty of experience with my own computer problems(bad motherboards, bad ram, etc) and never have the fans failed to power up.

I would appreciate any input. Thanks.

 

[mastertech01]

When you transferred the celeron system did you connect up the same drives that were connected to the Duron system? It could be a power fault within one of the drives in that case. Try disconnecting all cables to drives including data cables and see if it will power up. Also could be a PCI/VGA card shorted if you used the same ones.

 

[hawkeyewx]

Ok, I just redid the swapping of the Duron and Celeron motherboards. This time the Celeron powered up fine in the Duron case, so I can now eliminate that power switch and any other components in the Duron case. Meanwhile, the Duron installed in the Celeron case still does not power up at all. I think I can now rule out everything but the Duron cpu and motherboard as the cause of the problem. I'm going to install an Athlon XP in the Duron motherboard(The mobo is pretty old but it does accept the Athlon XP) so I can rule out the cpu.