Why you didn't ask me, I could have send you a good modded server PSU together with the BIG1 ?
until we get the pictures...
If it looks similar like this TaoBao "600W" FLEX: just forget it ?
Here is a real 500W FLEX with 80plus rating:
Important points to look at if you want to make sure it is a real 500W PSU with 80plus-isch efficiency:
- the cap (or caps) should have a value of something like 240uF
- the heat-sinks should be small (if it needs big heat sinks it is poorly designed and burns a lot of power)
- the inductors / transformers should fill up quite some space on the pcb
- good and efficient high power PSUs usually using E-Core inductors and not toroids
- since you cannot see which safety features it has, at least look if it has a fuse and the grounding wire connected correctly (e.g. not screwed on a painted surface but really making contact with the metal of the case)
- at your own risk: you can also check if it has standard safety features like over current and over temperature protection. E.g. if you short the 12V output it should switch off and not explode.
- observe the temperature: a good 500W FLEX stays cool under low load and barely gets warmer than ~45C under higher load