Back in December I had a machine (MSI Z97 G5 motherboard) drop dead. Fiddled with it for a day or so, then got back to work using other machines and let it sit until yesterday. Finally had the time to strip everything off because it was caught in a power on no post, reboot cycle with no way to get to the bios.
Pulled everything. Still didn't work.
In desperation I pulled the battery, let it sit for 5 minutes and powered up. It stopped the power loop, but would not post or allow bios. Put the battery back in. Boot, but no bios. Put a single 4gb ram in (had been running two 8gb ram) and tried again. Bingo. I got to the bios, reset. Powered off. Put the 2-8gb in, Bingo! Automatically went to bios with a "your configuration changed would you like to run set up?"
Put everything back in EXCEPT the high priced video card---which I think was the original culprit, having exhibited some funky behavior the previous 14 months of operation---and opted to use the on board Intel video.
No data loss, All updated, OS and programs and what I thought might end up as a pile of spare parts is back in production use.
Moral of story?
Might change the dang battery FIRST!