Can't tell Jandoste, I don't have your modules in front of me, and i'm not in front of mine.
It's hard to help someone with the distance jandoste, and solving problems as you may know can be complicated.
Assembling is always easier of course, but that's not electronics and DIY...
I understand that you fried the module when inserting it in the rack, so if after replacement of the "visually" defect parts nothing changed, than this means that something else is fried (obviously) and the only person that can find that out is you, you have a DMM tester, and I guess a lab PSU maybe? Good that you have a working module, that helps as well.
Going with the schematic first thing would be to see if the Power rails are feeding parts of the circuit etc....
Testing diodes, transistors with your DMM etc... Etc....
Finding the fault can be hard and takes time, but that's part of the deal, I wasted a LOT of time trying to solve issues, sometimes you get things quick and you're happy, and sometimes it's a PITA.
Cheer up, and get things Rollin, after all these kits you should be able to find the fault.
Write down what seems to be looking good and what's not to keep track, because sometimes it's good to take a break and get back to it so.....