[SOLVED] Unable to clear BIOS even after removing the battery?

[MandelaEffect2000]

Hey guys, I have a pretty odd situation here.

The computer is a mini-pc from Lenovo, model M75q-1 pertaining to the ThinkCentre Tiny Series. The model of the motherboard is printed on the PCB, it's a Lenovo AM4KIH (ver 1.0).

So upon fiddling with memory timings, I got a blank screen and computer would not POST. That's perfectly fine. Then I removed the case and tried to clear the BIOS via the Clear CMOS jumper, no success. Then I tried again by removing the lithium battery for 30 minutes before powering on the machine, nothing. The BIOS had not been cleared by neither methods.

How would you explain this behavior? Is it possible that residual voltage is still in the motherboard after removing the battery for a good 30 minutes? I have never seen something like this before!

 

[Math Geek]

try removing the bios battery and the laptop battery itself. with it all unplugged press and hold the power switch a few times. this will discharge any power left in the system anywhere. then use the clear cmos jumper with it all still unplugged. leave it for a bit and then finally put it all back together and try again to see if the bios was reset.

if that does not do it, then it likely is not possible.