Hi guys, I had an unfortunate event occur just now. I just got some powered risers was installing them on my mining rig. I have a Corsair HX1050 PSU powering a Sapphire 7950 with both 8 pin power plugs. The 7950 is connected to a powered 16x riser cable that is powered from the same power supply. This is the first time I had attempted starting the computer after adding the riser cable. The second I hit the main power switch on the PSU I heard a pop and saw a small spark by the riser connector and GPU, along with that lovely burning electronics smell.
Upon closer inspection of the card I can see that pin 2 near the I/O end of the card is melted. Could anyone tell me what happened? I've built dozens of computers over the years, but never used risers before. Any suggestions would be much appreciated!
You do not say if the riser is plugged into a PCIe x1 or x16 slot but it is most likely a bad powered riser that has solder creating a short from the first two pins which are +12v to either the third (which is unused on x1) or the fourth which is -12v. Clean the pins and plug the card into a good motherboard to see if the card has survived.
It is unlikely that the motherboard has been damaged as cables that could feed power back should have been cut but do a visual check of the PCIe connector and components to see if there is any damage.