Hello everyone! I recently got an amazing buy at an auction: a Kikusui PLZ334W Electronic Load for $11, and it works! They seem to go for ~2K USD new.
Not to worry! I've made sure to fix that pesky 'working' condition.
The e-load was absolutely filthy from use in an industrial environment, so I took it apart down to the individual board level and cleaned everything, then put it all back together. Problem is now the power switch won't stay in the depressed/on position for some reason. It definitely worked before, not sure how I broke it though. The device will power on and work properly if I hold the switch in manually - it's just an issue of the switch not latching.
I took the switch apart and have attached pictures. I feel silly saying this but I can't figure out how the switch mechanism is supposed to latch and stay depressed. The little round red/brown plastic bit that gets held down onto the contactor by a spring did pop out when I took it apart, but I found that and put it back in. The only thing I can think of is maybe another part of the mechanism flew out that I didn't notice?
If anyone knows of some pictures or a video of how the latch mechanism on these switches works it would be appreciated, maybe if I understand how the latch functions I can fix it.
Another option would be if anyone knows how I would go about sourcing this part. While I could use a Dremel and replace it with a non-matching switch, I'd prefer not to do that if possible.
It looks like I can only attach a couple pictures per post - I'll have to reply to my own topic to add the rest of the pictures.
Notes for anyone else looking to disassemble one of these: The blue plastic grate on the front shattered for me when I removed it - and I did not use excessive force. It has upward facing friction-hold hooks and detaches simply by pushing it down after unscrewing the two main load screws. Maybe for me it was just a matter of whatever it was exposed to over the years (aerosolized oil maybe?) - but anyway, I would advise holding the bottom to provide gentle counter-pressure and sliding it down slowly and gently as possible.
*Edit*: after looking up examples of how latch mechanisms work I realized there must be more there and was able to disassemble the switch further, where I found a broken plastic nub in the mechanism. If I can get my microscope camera setup working properly I'll add pictures.