04 Feb 2003, 09:10, Wayne Chirnside (1:275/311), wrote to All:

Hi Wayne.

 WC> Anyone know if installing a CMOS battery backwards
 WC> will damage the CMOS?

It never harmed anything the few times I reversed polarity, but that was on
older boards with the plug-in battery pack.  Only IBM boards had the (+)
mark by the four-pin connector, and they had it at the wrong end of the
connector!

 WC> I installed a new battery and it STOPPED the clock
 WC> despite putting it in as indicated.

Odd indeed!  Check the battery 'holder' for any signs of crud or corrosion.
 Some salts of copper or nickel act as diodes.  Make sure the contacts are
tight enough to actually hit the cell.  Some of the early cell holders got
pretty mangled by simply changing batteries.

 WC> I'm thinking of reversing it from what the holder is marked
 WC> as I don't ubderstabd this.

Normal position for the lithium coin cells is (+) UP!  (The large flat end).  

 WC> Clock holds fine when the machine is on with no battery.

Wish you had a meter to both confirm that the old one was in fact 'dead'
(and not something else), as well as being sure the new one isn't a 'dud'.

Check the CMOS to see whether it holds settings when off overnight.  Set
CMOS to show a "B" drive set to 5 1/4", then leave machine
off for about 12 hours.  Check CMOS again when you next start up to see if
the bogus setting remained.  

Loss of the clock during power-off is only an irritant, provided the entire
CMOS doesn't have to be re-setup every time.

One other piddly thing comes to mind, the "Clear CMOS" jumper. 
Both my dealer and myself have gotten bit by removing various jumpers, and
MUCH later discovering that the metal insert of the jumper was still
attached to the posts.  We had only removed the plastic 'shell' of the
jumper!


     Good luck...  M.

--- Msged/386 TE 06 (pre)