No power to PC - HELP!!

[Shadow911]

I have just finished building a new system. I have done this before and I need help in trying to diagnose this one.

I have plugged everything in and when I go to boot, there is no power running through the mobo. None of the fans on the board run and the fan on the PSU does not start either. No LEDs light up on the mobo. I have 2 power supplies and they both work but not on the new system.

I have removed the board from the case, plugged in CPU, Heatsink & memory stick and then all the power connections. Shorting the power switch results in no response.

Any ideas would be appreciated.

New System is:

P4 3.2GHz 800FSB w/512k socket 478 HT
Gigabyte mobo GA-8KNXP rev 2.0 i875p
1 GB Kit DDR400 PC3200 RAM (2x512)
ATI Radeon 9800 Pro VGA.
1 HD and DVD burner
(No FD actually - but should not make a difference)

I have reset the CMOS via removing the battery. I have tried different components on the mobo but no response from the PSU or mobo.

I am thinking that this is a mobo issue. Does the PSU fan spin when it is plugged in so I can rule out PSU or short issues?

Thanks

 

[satrow]

Follow faq602-2731

Andy.

 

[Shadow911]

Thanks Andy.

I have read through the FAQ. I might try and see if I can get another PSU and try that. I have the mobo outside of the case and still I get not response from the mobo when the power is connected.

 

[GrowingHaze]

You sure the outlet is alive? Could be circuit breaker.

-Growing Haze

 

[Shadow911]

Sure am. Tested other eletrical appliances in it.

 

[edfair]

Some motherboards will not allow power-on if the clear CMOS jumper is active.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[satrow]

...same with CPU fan on the wrong connector.

Andy.

 

[Shadow911]

Thanks Andy and Ed.

I believe these settings are right. I am going to try another PSU.

Let you know what happens.

 

[edfair]

If no leds on the M/B it appears that you have a problem with the keepalive circuits. Shold be 5v to the M/B, which then is used to bring power the rest of the way up.
Some PS fans will kick a partial revolution when power is applied but not all. The rest of the fans wait until the PS kicks on. And you are not getting that far.
Sounds more like a M/B. But you may want to dig deeper into the manual to verify that there should be LEDs when power is attached. I'm not familiar with the M/B so my responses are guesses.


Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[Shadow911]

Ok, this is the latest.

I have tested all the PSU's. One seems to be faulty. The others are fine. Funny enough, I switched the PSU to a different point in the place which as a power regulator on it, and it powered the PSU fans for 2 of the units (didn't work previously.

However, after connecting everything up, still none of the LEDs on the card light up. The fans on the board do not even respond. AND the PSU fan while works when not connected to the board, does not spin at all.

I think it is time to RMA the board back to Newegg.com.

Any other suggestions?

 

[Shadow911]

Has any one had any issues with clean power in NYC?

The PSU works when not connected to the mobo. But once it is attached, nothing. The baod may not power if it does not detect clean power.

Any thoughts?

 

[satrow]

It is not possible to test a PSU fully without it being under load. It may test ok without load but not provide enough juice under load.

Andy.

 

[edfair]

I've run them in a photocopy dealer where the other switching supplies clipped off the top 1/4 of the peak. They could still get enough to bring up the +5 on a noload condition. Just crashed regularly.

I've also run across several machines in the years where the input switch was set for 200 that worked fine no load but crashed (or failed to power up) when the load was applied.

Probably time for a VOM on the keepalive supply.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[Shadow911]

The load should be ok. I am using a 430V PSU and the only components on board are RAM, Chip, Heatsink, and AGP card.

This is too weird for me. Something is up with the power supply. I got another mobo and plugged everything in and powered it up. No response on that mobo either.

Not sure what else to do.....

 

[Shadow911]

Ok, I finally got the fans and progress made using a new Intel mobo. So looks like the issue is to do with the Gigabyte board.

I will be RMA'ing that tomorrow.

Thanks for everybody's assistance. Hopefully I don't have anymore issues when the new board arrives.

 

[DragonQ0105]

Is the Power Switch on the case correctly wired to the motherboard?

 

[Shadow911]

Hi GragonQ0105,

I believe so. The mobo has three pins (1 positive and 2 negatives). I attached the 2 pin connector from the case over the positive and negative. But so you know, I did try the other combination and switching it around (just in case I got the ground the wrong way around).

The second board I tried was easier. It plugged in fine and booted fine.

If you are familiar with this mobo, maybe you could clarify which way the power switch is suppose to go.

Thanks