Re: adult supervision for me & my 35 Message #3 Posted by Tony Duell (UK) on 8 May 2002, 7:56 p.m., in response to message #1 by db(martinez,california)
The only battery-related circuitry in the HP35 (or in other classics) are connections between the battery contacts and 2 pins on the charger connector. And a spring contact in the bottom case that connects the outside 2 pins of the charger connector together when the charger is not plugged in, and thus connects the battery to the rest of the calculator.
So, with the back case off, check for continuity (very low resistance) between the rear (display-end) -ve battery contact and the middle pin on the charger connector, and between the front battery contact and the outer charger connector pin that's not on the side of the machine where the on/off switch is (this is the clearest way I can think of to describe it). If either connection is open,
remove the logic PCB (it just pulls off the pins, but handle it by the edges to avoid static damage), unscrew the chassis plate, and check/replace the wiring on the back of the chassis.
If the connections check out fine, make sure the battery contacts really are clean. The connection to the battery pack is made via the 'sides' of the contacts and small
amounts of corrosion/dirt can cause problems
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