Why does the PC not turn on, turns on 1 time after the bios battery is re-plugged?

Question

Iron

Is the problem more likely in the battery or in the BIOS, or are there even more likely causes?

Answer 1

With such a formulation of the question - carry it to the SC.
There can be several reasons - a dead battery, a broken or leaking dual diode on the motherboard (by the way, the motherboard model and config are not specified at all!), incorrectly set jumpers, a problem with the BIOS flash drive (on modern boards, the same flash drive is used instead of cmos bios, it writes both UM and percent in the POST process), and the actual dying chipset (UM / PCH / combine (if in a laptop)), or even in SIO / MIO (EC) problems, it often also comes from a battery.
If you want to fix it yourself - formulate the question as fully as possible, and go to rom.by (and there maco will have fun with might and main :)

Answer 2

Apparently you're "perverting" the wrong way.