J. P. Gilliver (John) wrote:
On Thu, 20 Aug 2020 at 13:11:04, wrote:
[]
With the battery removed, I am going to wait 24 hours or more for
CMOS
memory to clear (did that on other HP laptop years ago). I measured the
You could short the cell terminals (e. g. put in a coin rather than a
coin cell!) on the mobo once you've removed the cell, which would
probably clear/reset it sooner. (With no power - mains or battery -
connected of course! And remember to remove the short/coin before
applying any power!)
[]
Which includes removing the wall adapter, the main battery pack,
the coin cell, *then* short out the socket as a means to
drain the last remaining supply (a tiny ceramic cap sitting
on the VBAT line). The purpose of the tiny ceramic cap is
to provide instantaneous current when a counter ticks
in the RTC well.
You should not short out the coin cell socket while power
is available. There is a charging circuit connected to the
coin cell, and we don't want to be shorting that out
while it's attempting to charge the cell. With all power
removed, it won't be attempting anything.
I'm expecting, if it is an LR20xx or ML20xx rechargeable cell,
that's not going to be available at the watch repair store
(a supplier of batteries). I don't even know if the Geek Squad
would have something like that. Locating one should be more
annoying than finding a CR20xx.
Hi Paul,
FINAL UPDATE:
Since the main battery was defective, only the case of the
battery (insides was removed some time ago), I decided to do
what I did with that other HP laptop (different model). I put
two AA akaline batteries in that case with a diode to prevent
charging those AA batteries (non-chargeable). Ran fine wires
to CMOS battery holder & soldered wires to contacts.
In order to bootup this laptop, I was unable to use F2 for
BIOS settings due to a PASSWORD prompt (NO clue what
the password is). However, I also had a diagnostics option (F10) and used
that to get defaults put into CMOS after a report that "CMOS checksum was
bad".
I am now able to use this laptop again.
Once more, Thank You for all your help, John