Error 472 Fronius IG Plus 11.4kW UNI Inverter

quique

I have had 2 ig plus 11.4 UNI inverters working for about 6-8 years.  A few months ago one of them stopped producing and had an error with one of the power stages (PS00, 01 or 02).  I believe the error was 308.  So I proceeded to call a local service company that was listed as fronius reseller.  They had me buy a new pnci board and replaced it.  The inverter worked fine for about 3-5 days and then started giving a 472 error.  I checked the grounding network where I found some faulty (corroded) screws and replaced them.  I also replaced the gfci fuse and the inverter worked for about 3 days and is now again giving a 472 error.

There are no other local service companies that can help which is why Im looking for help elsewehere.

Can anyone share their fronius experience in similar cases or perhaps suggest what I could try?

Mars