Selling used hardware and not mentioning the fact is bad. I am a bit surprised if you got your money back.

Not used per se but the box was opened and the the mobo was in an anti static bag that was not sealed. The manual had clear signs of usage as did the CD.

The hobo itself looked new and had that distinct new smell. No visible scratches or anything of the kind. However in such cases the description should say open-box or refurbished. If it says new I expect a brand new sealed item. This was the only listing I found that said New and had a significantly higher price. I was willing to pay the extra but if the item is not brand new I might as well buy the cheaper one.

Anyway Amazon is good at enforcing its sellers to refund in such cases. If all else fails I can easily do a chargeback.

Finally got time to install the new motherboard today.

Good news though: Installing the new motherboard fixed the issue. Finally!

Going to reinstall Windows anyway, although it seems to run fine anyway (had to be activated again though). Then run the usual memtest, prime95 torutue tests and GPU tests. Everything seems fine though.

Good if all is good now :-) Motherboard failures are irritating if you have problems finding a replacement.

Glad to know you finally solved the problem. Yup, a clean Windows install is best in cases like this. :)