Seems the platform for that unit is CWT-PUO1350V. jonnyguru did a review for that unit here. There were a few questionable things...mainly the power cord it came with (which is only an issue in a 115V system)...but overall nothing too bad. I think your main problem was having unpowered risers. A good rule of thumb is to run PCI-E power through the motherboard for no more than two cards...but the fewer the better. This includes cards plugged directly into the board and any on unpowered risers, but it's a good idea to only use powered risers. Anything more than 2 cards should definitely be on powered risers only. Use Molex rather than SATA for your powered risers, and don't power more than 2 risers on one Molex chain. Good luck with your RMAs.