@RappanzZ28 did you ever have any more issues after replacing the node board? Did you end using the same shaker that you originally purchased?
I have a JP Premium (about 2.5 years old). I had a Stern shaker installed on it for over 2 years (with the capacitor)...no issues. I moved the shaker over to my Godzilla Premium (while I waited for a new shaker from cointaker). Worked fine. New shaker from Cointaker arrived and I installed it on JP. It seemed to work (but not like the original one). Next day, received same 2 errors as your original post (i.e. Overcurrent protection on Node 1 and Trough error). No smell or obvious failure on node 1 board. Game seems to play fine but shaker doesn't work. I moved the new shaker over to Godzilla and seems to work fine.