Wierd P1900 problem on ACPI.

**mp5a4** · 09-25-2008, 03:00 AM

OK so i got a P1900
Everything is working well on my desktop trail other then one thing, the ACPI power switch thing.

My Mobo is a simple short to on type.
I connected the J3 jumper to my motherboard, simulate a ingation on and computer comes on

Problem is the computer does not turn on.
well the fans, HDD, CDs etc are all on but somehow it doesnt boot.

with a normal power swtich it works perfectly but somehow, no matter what i do or how i wire, when i connect the ACPI headers (on the 8pin or the J3) it doesnt work.

Now what i want to find out is what kinda signal does the ACPI heads on the P1900 gives? I juts need a simple short to ground but it doesnt seem to give me that. I have no touched any of the jumpers.

Thanks people.

**mp5a4** · 09-25-2008, 03:26 AM

The fun thing is, when i turn off the ignation switch, the compute rwill boot normally (before the P1900 times out and cut power)
So i am pretty sure its the ACPI header signal problem....

**rgarjr** · 09-25-2008, 12:18 PM

it think the acpi wires off the psu are just a relay contacts, kind of like pin 30 and 87 on a relay. So it can be ground or 5vdc, whatever the power button has on it on your pc.

**mp5a4** · 09-25-2008, 01:41 PM

Thanks for the reply
so is there anythingi need to do to make it just short the button?
thanks!

**skuller** · 09-25-2008, 01:44 PM

I am not sure about the carnetix, but some other power supply need to be connected to the switch with correct polarity.
Try to flip the connector and see if it works.

**rgarjr** · 09-25-2008, 11:30 PM

Check the two ACPI wires with a multimeter. Connect the 2 leads to the multimeter and check and see if the 2 wires are shorting out (a quick strobe) when you turn on the igntion.