M1-ATX auto-power-up the motherboard

**aiml27** · 12-05-2005, 02:48 PM

Hi

I've been happily using my M1-ATX in my car pc for about 5 months now - no problems. Just recently I added wi-fi support, and during the disconnection from the vehicle something went wrong - not sure what. When I was ready to put it back in the car, the M1-ATX J6 jumper which is used to tell the motherboard I want it to start/stop now doesn't function. The rest of the M1-ATX and motherboard work a treat - just this one thing.

My car pc used to auto-start 3 seconds after ignition and when ignition was stopped it would enter shutdown. Note I'm using the 5 sec/45 sec mode.

Anyone else had these symptoms?

I'm aware with problems on the v1.0 board which I guess I have since I bought it in about June 2005. I've never tested the HARDOFF mode as my VIA SP8000E-based car pc never fails to shutdown cleanly and within 45 seconds!

cheers for any advice.

P.S. I HAVE searched this most excellent forum for these symptoms, so no flaming ;-)

aiml27

**aiml27** · 12-08-2005, 08:16 AM

*bump*

**neon_eddy** · 12-08-2005, 08:46 AM

Make sure the jumper is on the correct end of the grouping of PINS

**aiml27** · 12-08-2005, 02:34 PM

thanks neon eddy,

I know what you mean but I checked this and confirmed I have the correct two pins on the motherboard it's attaching to because a quick short between these two on the motherboard does fire it up/shut it down successfully.

But when power is running through the M1-ATX, no voltage (even a quick pulse) ever reaches J6.

aiml27

**greenman100** · 02-18-2006, 11:30 PM

I have the same exact problem.

What's the solution?

**piabu** · 02-18-2006, 11:46 PM

Check your ACC line input wiring again. Does it go high (12v) when the ignition is on and go low (GND) when the ignition is off?

I do not know if this is related but I noticed that the M2-ATX does not reliably turn the mainboard off sometimes (turn-ON is fine) when testing on my desk. The workaround is to make sure I ground the ACC input line instead of leaving it floating.
M2-ATX feedback - ACC line

**greenman100** · 02-18-2006, 11:50 PM

yup, it goes high and low, I am physically connecting/disconnecting it

starting from the side of the board moving towards the middle of the board, there are 4 pins, 2 should be in parallel with each other. the outermost pin is ~.7v, ~.7v, ~.7v, 0v

the first and third pins are connected to each other. the second and fourth arent.

arggg

**aiml27** · 02-21-2006, 08:21 AM

greenman

Glad I'm not alone in this problem. I haven't got any further with a fix for this. I swear my ACC line goes high and low exactly when it should. I even forced the ACC line high manually by shorting it to the PERM +12V, and still no voltage across J6.

What do you mean when you describe the pins from the left? Are you talking about the pins on the M1-ATX PSU board or your particular motherboard?

thanks

aiml27

**bad-at-this** · 02-21-2006, 08:53 AM

I have a similar problem some times...When I turn on the car 1 out of every 5 times it will not cold boot, the fans spin but the bios never posts. For me its just a matter of turning the car to acc, letting the bios start to post (loud beep) then starting the car when this happens.

-Bad

**greenman100** · 02-21-2006, 12:59 PM

Originally Posted by aiml27

greenman

Glad I'm not alone in this problem. I haven't got any further with a fix for this. I swear my ACC line goes high and low exactly when it should. I even forced the ACC line high manually by shorting it to the PERM +12V, and still no voltage across J6.

What do you mean when you describe the pins from the left? Are you talking about the pins on the M1-ATX PSU board or your particular motherboard?

thanks

aiml27

I'm talking about J8 and J6 on the M1-ATX