Best of luck mate. Hope the new risers solve the problem 
To all,
My issue was solved using Claymore’s miner (windows 64-bit). It allowed me to control the temperature of the cards which was causing my cards to crash in the first place. Second, I achieved 200+ hash per rx 480 gpu. When I started my configuration I thought it was more difficult than expected. However, I used the tutorial at https://www.cryptocompare.com/mining/guides/how-to-mine-zcash/ . Expanding the memory and adding variables was a google search away. I also found the catalyst 16.? worked fine with claymore so I didn’t try to revert back to the older version recomended. The one thing i did do was set temperatures to 75c. I’ve been running my rig for 24 hours plus and its fine.
Roger