I had 8 of these and had to RMA most of them due to attempts at repasting and also just GPU death in general
I've also had mostly bad experience with 290s. Had only 5 or 6 of them in total, and 2 or 3 went bad within a few months (all bought new). Haven't ever had such high failure rates with any other GPU series.
What were you mining with them? If you bought new, I am assuming it was late 2013 and you were mining Scrypt which was litecoin.
From what I recall, the R9 290 was a complete power-hog with Scrypt and if you ran with stock voltage they pulled 350-400Watts per GPU easily and due to poor heat control, they easily burnt up.
Also earlier there were not so simple risers as we have now. I burnt one R9 290x after incorrect connection of additional power to the riser. It cost a lot at the beginning of 2014.
Yes back then we had to use the ribbon risers.
I remember people had issues with the powered risers due to the +12V line being shared with the motherboards and the PSU +12V rail.
Basically you had to make sure the +12V lines were cut and weren't connected to the motherboard because if they were then you got a feedback loop because the motherboard +12V wasn't exactly the same as the +12V from the PSU, even if you used the same PSU. And it was a quick way to destroy a GPU, motherboard and a PSU.