It's just about time to finish cleaning up the CADR. The shop-vac was taking huge flakes of rust off the vent at the bottom of the rack, but eventually stuff stopped falling out.
It's still pretty rusty but at least there's less floating around.
Next was opening the CPU; It didn't look too bad. Mostly minor surface corrosion.
All of that is wrapped as one huge board!
At this point I decided it was time to power on the fans and accessories to see if they had survived. The PDU has four standard house outlets that drive two power strips zip-tied to the sides of the rack. Everything is divided between the two strips.
I just plugged everything except the Mighty-Mite (which isn't reinstalled yet) into a spare power strip and plugged it into the wall.
Unfortunately, it seems half the bus box fans are failed; The blades are falling off the motors and binding against the plastic retaining brackets.
Pulling this assembly out for repair turned out to involve disconnecting the 5V bus bars and a lot of finagling...
Finally I got it repositioned to the bottom of the rack so I could pull the individual fans:
It turned out that not only were the motors full of crud, the retaining clips for the blades were made of plastic and all of them either showed cracks or had just plain disintegrated, leaving the whole assembly loose on the shaft. I'll have to visit the hardware store and buy new (metal) retaining clips.
Pulling and cleaning all those fans is going to take a bit, assuming that's all they need and not replacement, so in the meantime let's see where the Lambdas stand.