HP/Compaq not reporting CMOS checksum errors.

[sajunky]

Having 6715b notebook with flat CMOS battery. I didn't notice that date was wrong and Windows Restore messed up...
It doesn't support changing date/time in BIOS Setup, but I saw Compaq computers without ROM-based setup, no problem. Problem is that BIOS doesn't report CMOS checksum errors, it just loads defaults and continue booting (with wrong date/time set).
I replaced CMOS battery, but I'd like to know whether it is a feature, or something wrong with this unit. Please advice.
Re-flashed BIOS with the same version (F.07), no changes. Flashing took to long (in my opinion), about 3 minutes, but finished with no errors.

 

[sajunky]

Bump.
It is uncommon that CMOS battery goes flat, as main battery supplies power to CMOS clock and CMOS battery not get discharged. In this case main battery was dead for many months...

I think you might have to reset CMOS data at times. Did you ever notice that after resetting CMOS data the clock is reset, but BIOS doesn't report checksum error?
Asking, because laptop has a nice 1680x1050 screen, I want to use it.