Turn newly built computer on - nothing

Hi - I wonder if anyone can help.

I received today the final bit of equipment - Enermax Liberty 500 and installed it in my case.

However, when I switch on the computer - nothing happens, apart from a slight movement on the CPU fan.

I have an Antec P180 case, an Asrock 939SLI32 motherboard, with an Athlon 4800x2 CPU.

The system panel header on the motherboard is:
PLED+ PLED- PWRBTN# GND
HDLED+ HDLED- GND RESET DUMMY

I had all of these conected, but have removed them now other than the power connector. I have tried this both ways horizontally in PWRBTN# and GND.

I have tested the power supply with a tester, I had the following lights on:
+3.3V
-12V
PG
+12V
+5SB
+5V

However, -5V did not come on.

Can anyone advise. Dont know where to assume I have a problem, the motherboard, the P180 switch? HELP!

Sounds like your new power supply "is broke". You might want to verify the output rails with a voltmeter (a relatively cheap one can be got at radio shack probably, or bought over the web), but the -5V light off combined with not even the internal PS fan moving sounds like something inside ist kaput.

Check for internal fuses or circuit breakers to be sure they're not blown or tripped, but it might need sending back.

--dv

I only have a 350W psu, albeit with 24 pin ATX connector. Not sure if this will be OK for AMD 4800x2. Due to advice, I will try and get the Enermax swapped out.

I needed to understand if the -5V was important! Obviously it is.

Thanks very much. I have since removed everything from the motherboard other than the PSU and CPU and graphics card and it still is not working.

I have also connected the PSU to an older computer, and the same CPU fan judder happened but that was it.