hi guys,

playing around trying to resurrect a 1996 compaq deskpro 2000 with P166 in it..
the on board batt has died and as seeing the cell is soldered to the board i thought i would have a go using the external battery option that these systems support..

ive worked out i need a 4.5v battery (3 x AA will do the job).. Compaq 160274-001 is the official one but i will make my own, but it wont be keyed so can potentially put it the wrong way around.
so the issue is which is the + and - on the board..

i have tested with a multimeter and both outer pins report 0V .. with the middle being 4.5v, but from the looks of the battery it doesnt connect to the middle pin, just the outer ones..