Bad switch or not the switch? 2

[rirusstek2]

I have had this odd happening when I start the computer.

Sometimes when I press the start button on the computer the led comes on briefly and then nothing happens. If I press it again nothing happens, no led light, nothing.

As this has happened enough times I have noticed that opening the case I see on the motherboard a little green light being on. If I unplug the main power cord and wait several seconds the little green light goes out, then I proceed to plug the cord back, immediatelly the little green light goes on again, after this I press the Start button and the computer boots up perfectly.

This happens about 10% of the time and I have it patdown that when it occurs I unplug the main cord (the power supply does not have an on/off switch), wait several seconds, plug it back in and press the start button and everything is OK.

But if you guys have an idea that will help, I'll appreciate it.

The motherboard is an Intel D850MV -WinXP Pro - P4 2.2GHz - 425Watts PSupply

 

[edfair]

Symptom of a problem on the N/B. The led on the board indicates the monitor circuit power and the led on the case flashing indicates that the power is trying to come up but the M/B isn't keeping it up.
Can also be a P/S problem but more likely the N/B.

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

 

[franklin97355]

Make sure the power cable fits tight in the power supply socket.

 

[rirusstek2]

OK ... Now, I've tried to substitute the N and the B and haven't come up with an answer and I just have to ask: which is the N/B? or what is the N/B? Sorry to ask.

I've replaced the power cord for a newer one hoping it is tighter. So far the "symptom" hasn't occurred yet.

 

[edfair]

Sorry, right index finger found the wrong key , should be M/B for motherboard.

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

 

[rirusstek2]

Well .... thanks for clearing that up, but now I'm worried.

That means a new M/B?

 

[edfair]

That is a distinct possibility. Pressing the power-up activates the portion of the M/B that controls the power supply. The circuitry is also used to power down the system. And generally a problem there leads to replacing the board. Not always, but enough that you need to consider the possibility.

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

 

[LloydSev]

I would bet it's a PS issue.

Computer/Network Technician
CCNA

 

[rirusstek2]

Well, this is what I've done trying to figure out the reason for this "sometimes not turning on issue" ......

I unpluged and replugded ALL of the MOBO power connetions, and No it wasn't that.

Then I pulled out the PSupply, cleaned it out and while doing this I noticed that the 115-240 voltage change switch was NOT all the way to 115. I pushed it until I felt the fully seated "click" and installed the PSupply back in the computer.

So far I've shut down and restarted about 12 times and the "sometimes not turning on issue" hasn't occured.

Could this be it?

I'll let you know if it happens or doesn't happen again.

 

[paparazi]

rirusstek2
Yes it could be it!

I agree with edfair on this one but swap around the probabilities, PSU first then motherboard.

But the switch could have been it!
Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[edfair]

I've seen my share of machines with the power supply switch set wrong and turn-on has never been the problem. But we all go thru life wanting to learn something, and this may be a learning experience.
You could switch it back and see if the problem returns.

And it may be that the specific power supply has a problem with the 5v keep-alive circuits that make it sensitive.

 

[jurgen36]

I would say power supply. This usually is a fault if the supply can not deliver sufficient power for all devices. Had the same problem in many machines. Modern CPU's and graphic cards use a lot of power and cheaper supplies can not deliver it during start up. This is regardless what the ratings say. Change the supply and it will be ok
Regards

Jurgen

 

[rirusstek2]

Thank you all for your great help, so far I've not gotten another "sometimes not turning on issue" after I fully engaged the 115-240 volt switch.

The power supply is a TURBO-COOL 425 ATX. I installed it about a year ago and really don't know if the 115-240 switch was not fully engaged since the begining or it happend during some clean-out recently.

So far so good with the engaging to the right position.