[PLUG] Hardware recommendations

Jim Garrison jhg at jhmg.net
Mon Sep 10 20:37:59 UTC 2018


On 9/10/2018 1:02 PM, Rich Shepard wrote:
>   Yep. This was the catch of the day. The motherboard manual showed me
> where
> the CMOS jumper is located and provided explicit directions: move jumper
> from pins 1 and 2 to pins 2 and 3. Wait 5-10 seconds (I waited 10). Put
> jumper back on pins 1 and 2. Boot system into the BIOS setup and reset
> system date/time.
> 
>   Sure enough, after doing that the system _paused_ at the screen where it
> had stalled then went on to boot. Replacing a dead CMOS battery was a new
> experience for me so clearing the CMOS real-time clock was required.
> Nothing
> other than the date and time were changed in the BIOS settings.

Clearly something in CMOS got wonky (technical term for "corrupted" :-)

There's a capacitor in the circuit that keeps the CMOS powered for a
short time (minutes) so you don't lose the clock and custom settings
when you replace the battery. The jumper shorts the capacitor and
battery across a resistor to completely remove power from the CMOS and
force it back to factory defaults.

>   Another new experience where I could not use prior knowledge to fix the
> problem.

--
Jim Garrison
jhg at acm.org



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