BIOS showing invalid info, time resets every time shut down.

Rats, it's actually soldered in place. That requires a good Computer shop to replace it unless you have good soldering skills, a good soldering iron and a solder sucker.

And there is no guarantee this is the problem. It probably is but the only way to know for sure is to replace it.

How old is the new motherboard? Did you buy it new or used?

That's old enough for the CMOS battery to be bad.

??? Don't understand? If you're asking how old it has to be for it to be dead, there is no way to a know.

Please let us know how you make out and if that is the problem or not. Thanks