Only one POST, unless cables reseated

[Remco32]

I'm building myself a PC, but I can only get to POST once. Once I POST and restart the computer, the fans start spinning for a second, and then shut off. If I reseat some cables, it sometimes allows me to POST another time. But after a reboot the same thing happens again.
Any clue how to fix this?

 

[clutchc]

Is it a new motherboard? Sounds like the CMOS battery is about dead. Try replacing it. When it goes, the system can't run the boot pgm in BIOS.
http://www.computerhope.com/issues/ch000239.htm

 

[tsnor]

Read this: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-boot-video-problems

I thought "the fans start spinning for a second, and then shut off. " was a short or failed PSU. I'm thinking the cable wiggling timne gave the power supply time to reset. Consider the 'bread-boarding' described in the above reference.

Standard debugging is to pull parts until the system posts. In your case pull all PCI card, memory, etc and see if that lets the PSU stay on. IF so the last part you pulled is suspect. Try putting it back in, sometimes reseating a card can fix the problem. Also follow all the other advice in the reference, like making sure that the right power cables are plugged, standoffs are using, cables are not pinched/sorted, etc.

 

[Remco32]

I got the PC up and running. The problem were the RAM channels. For some reason the MoBo didn't like having 2 sticks of RAM inserted at the same time.