auto power on

[CNS]

I am working on an intel mb model # d945gnt

Customer brought desktop (win 7 pro) in stating that it turned on itself and auto shut off. I plugged power in and it auto turned on and noticed that it turned off in about 20 seconds. NO Bios check, no beep, no windows logo, just a black screen. I switched the PSU and same issue. I removed all hardware so basically its just power to the MB and still same issue. Im thinking its a mb issue but is there anything else I can do on this?

 

[Jobrien]

So it doesn't come on at all when the customer wants it to come on... or does it always shut itself off?

 

[CNS]

it doesn't come on when you press the front panel power button, however if you unplug the power cord from the PSU and then plug it back in the mb attempts to boot up (fan spins) then it turns off in about 5-10 seconds.

 

[CNS]

im gonna test something out, but i don't see an issue with the MB/components, etc. I suspect that perhaps the power button on the front panel has maybe shorted out and is causing issues. I don't see how the motherboard and fan will turn on automatically unless there's a power leak somewhere. But then, what is causing it to turn back off. confusing!!!

 

[BDNTech]

It is most like turning on when power comes back due to the bios setting auto start when power resumes. It is then turning off because either the mobo is bad as suggested or something else is preventing it from starting. I would remove the components one at a time while using the power cord to restart.

 

[CNS]

i have already removed all hardware components and duplicated the issue with CPU/FAN RAM and still same issue.

I would say a bad MB or a bad Power connector from the front panel.

Has anybody experienced an issue such as this?

 

[Rob_NNCC]

Yep. I had one mobo that was doing exactly what you describe. The only way I could get it to post was to hold down the power button when it first turned on, then turn it back on again as soon as it powered off. Bad Caps....

 

[CNS]

ill work on it tonight and give a status of what I find. I have searched this in google and have also went to intel community and i cannot find an answer anywhere.

 

[Adept PC Repair]

Rule out the power switch by using a screwdriver on the 2 power pins.

 

[CNS]

i removed the front panel and hooked up directly to the PSU. The motherboard would not POST. I used another HDD, still no post. I have ruled it out to a bad MB or CPU, but my bet is the MB.

In time, the motherboard would not turn off but would not even post either, then it eventually came to a point where it would not power on anymore. It appears that the MB is deterriorating as i continue troubleshooting. I'm gonna call this one a bad MB... CASE CLOSED!!!