[piotr]

Thanks for sharing that info. Negative (center positive in that case) voltage is bad for the Field Kit FX, so most likely your internal power supply is now damaged. Again, you could verify this by trying it out in your modular case - I expect it to still work.

If you look at the bottom board - top side with all the components - very close to the left of the DC input jack you might be able to spot a tiny, damaged IC with 5 legs.

And that small portion that was cut out of the board was done by us. There was an error in the production files of this Field Kit FX batch and the location which has some copper cut out, there was a connection that shouldn't have been there. Doesn't look great but was necessary.

Hi!
So I'm back with some photos. Is that the one IC you've mentioned? I just want to make sure that this is the one which should be checked/replaced in order to fix 9V / wooden case powering.



 
I'll try 12V Eurorack powering in next days, I just need to take FIX KIT back to other location.

It will be very helpful if you could let me know exactly what part is broken (any serial numbers, producer, SKU). Is it something similar to this IC: LM27313MFX? I want to be sure i'll buy and replace the right one. 

Thanks for your help!