[SOLVED] Power up problem...

[PROPATECH]

Hi Guys,

I'm having a really hard time trying to figure this one out. Please Help! I am working on a Acer Aspire M1900 desktop. The problem is when turning on cpu fan runs for a few seconds then everything shuts down. So far I have tried,

- Tested power supply, all seems good
- Tried new power supply, same problem
- Tried new motherboard, same problem

So I decided to go back to barebones and disconnect almost everything from the motherboard only leaving,

- CPU
- ATX
- ATX 12V
- Video card
- One stick of RAM

I then proceeded to re-install components one by one, disconnecting power from the wall and shorting the power switch pins.

All components booted into Windows with no problem except the front panel header. So I checked wiring and all seemed good on the single block. I then changed wiring from single block to individual blocks for power switch, msg, hdd led, reset switch, but I still have the same problem...

Any help would be greatly appreciated

Thanks

 

[Rob_NNCC]

if I understand you correctly, the system will not post unless you have the front LED/Switch header block unplugged.

Then you tried breaking out the block into 2 wire blocks for each item, but it will still not post if you have them all pluged in. What happens if you just plug in one at a time? Could it be the reset switch is bad, one of the LEDs is shorted?

 

[PROPATECH]

Thanks for your reply Rob_NNCC,

That's exactly what I have done. This model came without a reset switch so we can eliminate that, but the problem still exists

 

[N E Day Pc Repair]

Did you test all the ram individualy? I had that prob once on an old e-machine and it was a faulty stick of RAM. Also is your RAM mixed brands or all the same kind. I have been told that mixed ram can mis-behave causing weird issues.

 

[FremontPC]

If you connect ONLY the wires for the power switch to that block, will the system boot?

If not, remove the connectors for the power switch and momentarily short across the pins for the power switch.

If the system boots, then the pcb for the front panel may be defective.

 

[PROPATECH]

Thanks for all your help Guys, much appreciated.

Problem solved. It was the actual switch itself.

 

[ComputerRepairTech]

I figured that was the case when you mentioned it booted without the front panel connector but wow I dont think the idea would have come into my head to try without it until after I made the same replacements. I will have to keep that possibility in mind in the future.