E3634A repair and need firmware

[vtp]

Would anyone happen to have later than version 1.6 firmware for the Agilent E3634A PSU?

According to the crappy BOM in KS parts site there should be later available from somewhere, but certainly not from KS according to my experience with them. For some products their support seem to suck.

I have a couple of these in pieces in cardboard boxes and would like to update the FW on the same go as they get repaired otherwise. Blown current shunt, melted pass transistors, blown opamps etc...

[carl_lab]

What's the benefit of the "newer" firmware?
I worked with different E36xx and never noticed a problem by firmware bugs...

[vtp]

One unit had a broken rotary encoder. It did not take too long to find out what appears to be identical replacement for the original ALPS encoder.

Bourns PEC16-4015F-N0024 seem to fit perfectly and is available from Mouser and Digikey for a whopping $1 or so each.

One thing to note is that the Bourns encoder came with a large washer. I left the washer between the encoder and front panel plastics to make it keep the folding tabs on the encoder body together. I suspect there is some play in the mechanics which allows the shaft support to wiggle and then break the whole encoder. Not it looks to be nice and snug fit.

Looking at the schematics has made me wonder what was the idea of putting crowbar behind the expensive current shunt. Pass transistors short -> OVP crowbar on -> eventually very crispy current shunt. The crowbar does not even blow mains fuse and there is no fuse after the mains transformer to blow.