I'm planning on keeping the battery charging board in the unit but I do not plan on using it. The battery board connects to the main board, and if it's disconnected, the DMM will not turn on. A sense line goes up to the battery board and then back down to the main board. However, it's possible to allow the unit to operate without having the battery board connected if a jumper wire is installed. You can see in the first pic where the jumper wire goes. It actually will cross over the connector to presumably indicate to service personnel that the connector is not to be connected.
It's interesting to note that there was a jumper on the board and it's been clipped off. I have an HP 3466A with the battery option and it's the same way. It looks like they manufactured them with the jumper by default, and the units that were to be shipped with the battery option have the wire clipped at the factory. As you an see in the second pic, it does now work without the battery board plugged in.
Take a look at the third pic. I repaired the corroded wire that plugs into the battery. On both the battery wires there is a
very tiny plastic washer or grommet or
. I have no idea why that is on these wires. I've not seen these on any other wires in the unit. When I replace the wire I put it back on, but I don't know what it does. What purpose could they serve?
What purpose does the little plastic washer serve?