Hello all,
I'm refurbishing an HP 8640B generator. I eventually lose output and I've traced the problem to the slider switches on the filter board, A10A1. They've all been disassembled and cleaned. The contacts affected seem to be to the left of the aluminum slider clamp. Light finger pressure will sometimes bring things back to life.
The finger contacts all appear to be in good condition and not mis-shapened.
There are two very thin shim washers between the slider clamp and each clamp support. Proper operation seems to depend upon the tightness of the clamp screws. Is there a proper procedure for setting up this section? The service manual doesn't mention anything. Thanks for any help.
While I'm at it, I've had success with repairing a cracked delrin gear. Having removed the gear, put it in a refrigerator's freezer compartment for a few hours. This is an effort to cause the delrin to shrink more than the brass hub. Drift out the brass hub. Mine came out with just a gentle tap on a hammer and drift.(Credit the next part to Jeff Liebermann). Use 24 hr epoxy to glue the Delrin back together. Use a round file to open up the delrin centre hole so that the brass hub will just fit back in. Epoxy the hub back in.
One poster has suggested soaking nylon / delrin in warm water overnight will restore some of it's pliability. I did this to all of the delrin gears. Don't know if they're more pliable, but they're sure nice and clean! Ken