Computer not booting.

[stewie-Y]

Hey there. I have here a computer that is not booting for me(It's not the same one as in my other thread).

When I hit the power button the CPU and case fans spin but the power button doesn't light up and it doesn't initialize the monitor. I plugged in this POST diagnostics card(as seen here http://i.ebayimg.com/t/PC-DIAGNOSTIC-4-Digit-CARD-Motherboard-POST-Tester-/00/s/NzAwWDcwMA==/z/eCAAAOxy4t1SgcWV/$_3.JPG) and 5 LEDs light up(-12V, +12V, +5V, +3.3V, and RESET). Looking at the paper that came with the card it says this for Reset: "Lights only for half - second when you slide the power switch or the reset switch. If it is lit all the time, check the following: make sure that the reset pin is plugged properly, or the reset circuit is broken."

Doing a quick google search on reset pins I get different results so I'm not quite sure what to do at this point. Any help would be appreciated, thanks!

[Lisa_maree]

Hi

If the reset light is on then the motherboard is in a reset state so there will be nothing on the screen.

You could try disconnecting the reset switch from the motherboard and see if the light goes out.

If it does then the reset switch is  stuck or there is a short in the cable between the switch and the motherboard.

If that doesn't clear the reset then it could be a motherboard fault .
Or the power supply isn't releasing the power good signal or that the power good signal is too short, either of these you would test with a powersupply tester or oscilloscope.



 

 

[stewie-Y]

The computer only has the black/white(Power SW), green/white(Power LED), and red/white(HDD LED) switch cords. It never had the blue/white reset switch but this never was a problem. Any idea what else might be causing this? Something that I'm not seeing stuck?

[Lisa_maree]

Hi

Just to confirm you haven't moved any of those connections since before the computer was working. If you put a HED led on the reset pins it can hold the board in reset ?

Even with the computer turned off but plugged in does the reset led light on the post diagnostic card ? 

There is still the power good on the powersupply is playing up