Thread: getting an odd motherboard to power on

This might not help, but I had a similar problem. First try to power you arise with a car battery and see if it will post. I hade an old AT PSU that I was using to power my Arise but the only way to get it to work was to plug the old AT PSU into an old motherboard. After doing that it would power up my arise.

OK to clear up this little P13 connector business:

With original supply:

Red: always +5V
White: with computer off, +5V, with computer on 0V
Ground: well its ground...

This white wire is the only one that ever changes. All the P8 and P9 wires are all normal voltages no matter what. This white wire seems to turn on the original power supply somehow. But I don't know how to reproduce it because not connected to anything (power supply by it self, just plugged into wall) the red and white both are +5V. I don't understand how the motherboard can change this +5V if it is coming from the power supply...not the motherboard.

The power button connects to the [B}motherboard[/B]. It is a button and is only "on" for an instance...it is not a switch.

I just need some help understanding how the motherboard decides to turn on.

Telek, thanks for all your help. I have emailed Siemens asking for information. I'll keep you all updated if I solve the situation..so some poor soul doesn't have to go through this....

jssaggie, the problem is not getting my AC-DC AT supply to turn on...just the motherboard.

Again thanks for all the help. I'll try some new ideas once I get off from work.

Nate

ofr the P13, what happens when the computer decides to power off, does it change again?

It would be quite easy for the motherboard to just connect the +5 and the ground, and that would signal the power supply to power-on. perhaps when 5V is fed back into the white wire it'll power off again, I dunno. That's about all that I can think of.