I was helping a friend fix his pc.
Using mine to slave a drive, to save data prior to re-installation of the OS on his.
Several things were done, to make the job progress, but the bottomline is this:

Everything back to normal on mine, at reboot, my pc failed POST.
I recall it having to do with the CMOS.
So, I pulled the Bat2 jumper with the power off, replaced it as recommended on 2-3 instead of 1-2 pins, then put it back on 1-2. Powered on, with a "cleared CMOS".
Nope.
Now message shows "bad checksum" "defaults loaded".
Well, hit F1 to continue (general info) or hit Delete to enter setup are the only options.
Neither does anything.

I've checked cables & jump pins.
Pulled the battery and tested it. a 3V Toshiba battery about 3 years old tests at exactly 3.06V with a Fluke meter.

any thoughts?

yes, I had that one too.
I'm too proud to admit to idiocy though.

Did you reset the Drive jumper from CS or slave to Master when you moved the drive back?

I think the master drive remained that. A slave drive in my pc was previously unconnected at ide cable (center) and power. I connected the drive I'd be using in the friend's pc to those. When finished copying files from it to my master HD, I formatted the HD and disconnected it. Placed it in the friend's pc and continued by loading his winXP home. Came back to mine thinking I could leave the cable connect/power connection unhooked and carryon business as usual. I'll double check it in the am. Good question.

you were right.
I had it set on CS.

the pc is back up & running.
my mystery "woodpecker" is gone, the main cause of my perplexion for months now.
still, I experience frustration(s).
most draw from the fact that i need to study more than i have been, the natural consequence of having diverse areas of "timesinks" that don't include just my pc.

thanks for the answer.

Always a pleasure. Take care.