Confusing no power issue

[dowhopdedodo]

I'm having a problem that's perplexing given I'm using a Seasonic PS, albeit an OEM version. I've built the machine. No problems or confusion with assembly. When I turn it on, nothing. Not even a flicker, once. I've gone through the PS Switch and Reset connections from the case to verify and test. Everything looks in order. I've plugged and unplugged the PSU, switched and unswitched, nothing.

I did notice when building that the power connecter socket on the board is a 20 pin socket instead of a 24 pin. The PSU connector has the four extra pins able to swing out of the way for 20 pin sockets. The separate ATV 12v connector is connected to the board as required. Short of a failed PSU (that's never run) or a failed PS Switch on the case, or switch connectors on the mobo, what else would prevent poweron?

Thanks in advance.


ASRock ConRoe1333-D667 R1.0 LGA 775 Intel 945GC A2 Micro ATX Intel Motherboard - Retail
G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-2GBNQ - Retail
Seagate
SAMSUNG 20X DVD±R DVD Burner Black SATA Model SH-S203B - OEM
Seagate Barracuda 7200.10 ST3250410AS 250GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM
CoolerMaster Centurion 534 case
SeaSonic SS-500ES ATX12V 2.2 / EPS12V 2.91 500W Power Supply - OEM
E2180 BX80557E2180 SLA8Y

 

[BladeVenom]

A short. Make sure the back of the motherboard isn't touching anything.

There's also the simple stuff. Make sure the power supply is switched on. I've accidentally turned one off while moving a PC. Make sure the plug hasn't come loose.

 

[dowhopdedodo]

Hmmmm... it mounts on those brass spacer fittings. So, I'm not sure what could be touching there, unless I mounted more than appropriate, which would put one against the board. Better check.

It never gave the slightest indication of a power on though, not a hint. Seems like a short would give you some indication of a draw. But, it's only my second build, what do I know?

Living and learning...

 

[Fullmetal Chocobo]

Use a paperclip to connect the green wire & a black wire in the PSU 24p (or 20+4 pin I guess) connector. This will power on the PSU to see if it works, thus eliminating one issue. And don't worry, you can hold the paper clip and do the test--it won't shock you.

 

[dowhopdedodo]

Originally posted by: Fullmetal Chocobo
Use a paperclip to connect the green wire & a black wire in the PSU 24p (or 20+4 pin I guess) connector. This will power on the PSU to see if it works, thus eliminating one issue. And don't worry, you can hold the paper clip and do the test--it won't shock you.

Thanks, I found this on Seasonic's site just after posting, and as luck would have it nothing happened. Looking on the bright side, at least I don't have to run around checking for phantom problems.

Thanks for the tip.

 

[Aarondeep]

Check the voltage switch on the back of the PSU make sure it isnt set to 220V. I've built alot of systems and have actually run into this problem more times than you would think. =)

 

[dowhopdedodo]

Originally posted by: aarondeep
Check the voltage switch on the back of the PSU make sure it isnt set to 220V. I've built alot of systems and have actually run into this problem more times than you would think. =)

OEM PSU that has no switch apparently, at least none that I can find. At $69.99 and with free shipping it's not a bad price, if only it works I haven't seen any reports of similar problems however.

Bought from NewEgg, which is overnighting a replacement and covering return shipping of the original (rare in my limited experience).

I do apprecitate the feedback, a lot. I've learned three important things, although one probably doesn't translate to other PSU manufacturers (or Seasonic resellers).

The first, count the number of mounting holes in the motherboard before mounting the spacer fittings. Seems like a no-brainer, but I had nothing to refer to when Black Venom suggested a short at the back of the board as a possible cause. I couldn't imagine it, but then I realized something like one too many mounting nuts could cause just that.

The second, your tip. The third, if it's Seasonic, verify the PSU using the paperclip trick.

Thanks again.

 

[Saiyukimot]

So it was the PSU dead? You got a new one now that works?

 

[dowhopdedodo]

Power supply was DOA. Replacement arrived and it posted immediately after install. Wish my overclocking efforts were going as successfully.