Spontaneous BIOS reset

Question

BIOS

Good afternoon!
On one machine, the BIOS spontaneously began to reset.
After the initial check of the system, the message "press F1 to run bios setup" is displayed.
I go in, I see that I don’t need to change anything and I press save and exit
. Of course, I replaced the battery. But after off / on - again the requirement to install the BIOS. The BIOS itself is new - graphical, with mouse support.
Where to dig? What else could be the problem?
System:
CPU Intel Core i3-3220 3.3GHz 3Mb 2xDDR3-1333 HDGraphics2500 TDP-55w LGA1155 BOX w/cooler
ASUS LGA1155 P8H61-M LE H61 2xDDR3-1333 1xPCI-E DVI/DSub 8ch 4xSATA GLAN mATX
Thanks in advance!
UPD:
- the battery is normal
- on the motherboard, all visible elements are not swollen, not melted ...
- if the system unit is not disconnected from the mains (turned on through the pilot), then the reset does not occur. If you turn it off and on right away - everything is ok. Disable and enable after 2 minutes - reset.
Are there any other ideas where to dig?

Answer 1

Yes, check the battery contacts, and is the jumper on the BIOS reset

Answer 2

BIOS for a full flashing using FTK , if it doesn't help, write in the comments to the question.