|As Richard59 said, time will tell. You should have asked before you bought it.|
Two things jump out at me: it's an ATX12V 2.0 unit (current standard is ATX12V 2.3) & it has a 46A rating on the +5v rail. Who the heck needs 46A on the +5v? No one! Loading up amps on the +5v is a trick some manufacturers use to inflate the overall wattage rating. This PSU is no where near being a 500W unit. It's a 400W unit at best & even that may be a stretch. You paid too much for a low end PSU.
Here's a 380W Antec ATX12V 2.3 that's 80+ certified, has active PFC, a 3 yr warranty & it's only $40. What's the warranty on the Zumax?
For $5 more, here's a 430W Antec:
And that's just the beginning. I could post at least a 1/2 dozen others that cost the same (or less) & are better than the one you ended up with.