Thanks to Eyeboot, I got a new heatsink for that R3. However I think you'll notice something wrong in the picture below. Same unit. Not even 30 days in. Using a pretty nice 80plus gold PSU to run it at stock speed. I don't expect much given how the overheating issue was handled but thought others might like to see this. Again, I got 2 and the 1 running right next to it has been fine. I've tried to RMA this twice now, and people just quit talking to us.
https://i.imgur.com/oOlQNGU.jpg
Can't see in the picture - is either of the burned pins (in the red PCI-E plug or in the white socket) pushed in? Typically this happens when there is poor contact and that can be caused by slightly misaligned pins. They don't go into each other, you force the plug, and one of the pins gets pushed in or bent resulting in bad connection, heat, sparks, and melted plastic.
I'll take a closer look but tbh, this unit has been a dud since the beginning, see my earlier post. I've connected enough cables to enough miners to know not to force and make bad connections, and really RockMiner needs to replace this unit for me.