Disappointment with net6501

I've to say, after 4 years of using net6501, I am disappointed.

Mine net6501 was bought in 04.2012 and worked till 01.2015 stable. After that, the mainboard just died. There were several posts here on this list about that problem, as I was not the only one.

Thanks for my reseller, I've got replacement. But now, only a year later, the problems are back. Again, sometimes, the red LED does not go off and no POST at all.. or total freeze, even during POST. I've already tried a PSU from a working net6501, which did not solve the problem. So I guess, my mainboard is dying again slowly..