Maybe it's because the psu is garbage? I only have the CX500 myself due to budget constraints (whole machine for sub-$600 usd). At one point a few years ago, they were solid. Much better psu's for the same cash are now available. I wouldn't buy a current-era Corsair PSU at gunpoint now.
The early AX860i on the other hand...
"Masochism is a valuable job skill" - unknown
NZXT Classic Series Club