ErichV

Will do and let you know. Probably only next weekend though. 

I opened it up today and replaced the 2 x 1000uF caps on the mainboard that are usual suspects in these inverters. But it did not fix it. Inverter powers up, but then it doesn't start inverting. No relay clicks. Just shuts down again after a minute or so. I'll start pulling out relays and check if there are any faulty ones. Maybe I'll replace all the caps around that power supply circuit.

I sent an email asking for help with my parallel settings and dongles this morning. It was done at 10h00.

.......and it worked for 24h, then the same symptom again. Shuts down. Replacing it now.

So my Dad opened it up and let his electronic technician friend have a look. Couldn't see anything visibly damaged or burnt. He did solder one spot that looked like a dry joint. Put it back together and has been working fine for a day now.
Who knows for how long but we can only hope. It is going to hurt the pentioners' budget if he has to replace it now.