Serviceing my personal Matrix 5000 lower unit(s) - need experienced assistance

[BillP]

So we rebuild batteries and upper units all the time, but my own pair of Matrix 5000 units started to act odd when the transfer switrches would kick in during testing, etc.

Then one unit had a lower fan fail.

So, I now am about to take a dive into the lower unit(s) to service and clean them.

I hope they are okay, and survive my efforts. 🙂  (I about died putting one of these dang things on a bench!

Do any of you have experience with these lower units in this regard?

What can I expect?
Are there Schematics?
Do you have images of good units for comparison?

Any advice or tips on what to do while I'm in there other than clean and check everything?
(and replacing the fans)