M2-ATX wont boot....yes, i searched

**Qwicker** · 02-05-2007, 05:21 PM

Hey everyone, I've been looking around and i can't quite find a similar problem to mine with my m2-atx. I have everything hooked up, and when I turn on the ignition, the mobo does not boot. After about 5 seconds of ignition, the green LED on my motherboard becomes active, indicating the board has power, but then thats it. Now i read that there might be some timing issues where the on pulse gets sent before the rails are fully powered. So i decided to remove the relay for the on pulse, and just put a manual switch on the motherboard. So basically the M2 just gets power when ignition happens, and i start the mobo manually.

Well I tried that, and it still wont boot. I dont understand why if i push a manual switch (Not off J9 btw) while the board has power (green LED) it wont boot. I take the mobo inside and hook up an AC PS, and presto, it boots right away when i press the switch (green LED is on, of course before I do so).

Sometimes the M2 works, sometimes no.....I dont understand why I cant manually boot the mobo. Ideas? Thank you!

**legacy05gt** · 02-05-2007, 05:32 PM

Hook it up inside and go into the bios, there should be a setting to boot on power rather than via the manual button.

Information which would help answering this question:
Motherboard model

**Qwicker** · 02-05-2007, 05:36 PM

The mobo is a Gateway. I am not positive of the model, but its a P4 1.8Ghz. 20pin ATC power connecter plus 4pin P4 connector. The M2 has powered my mobo before correctly, but lately, not so much....

**legacy05gt** · 02-05-2007, 05:52 PM

what is the bios setting on the mobo for power-up? Unless there was a hardware problem with the M2, than some setting must've changed on the mobo. Maybe the bios was reset to default settings.

**Qwicker** · 02-05-2007, 05:52 PM

If this helps..... I switched the setting in BIOS to power on after power failure. So i powered up the mobo inside, then i bring it out to the car and hook it back up. I turn on the ignition and things start working. The processor fan (12V) and the hard drive were definitely spinning, but keyboard, VGA nothing. USB was delivering power though. I do not know whats going on here. Something else to note is that if i remove the power supply wires from the M2 while the computer is running, I cannot get it to boot again. I have to bring it inside and boot it with the AC supply. Then i can bring it outside and it will boot, sometimes only partially like the fans and HD, but at least its something......maybe my M2 is a piece?

**Wiredwrx** · 02-05-2007, 06:44 PM

Have you run a power calculator in your system.

The P4s draw GOBS of power. Do you have Video Card? If so, which one? Vid cards are VERY POWER HUNGRY as well.

I think you are over the power available frm the M2. And, before you say But it is 160 watts, and my system onlydraws 150, make sure you check EACH INDIVIDUAL VOLTAGE RAIL, not total wattage.

Michael

**Qwicker** · 02-05-2007, 06:58 PM

Hey, i do not have a video card. I use the integrated video. I did a power calculation, and i only need about 140W peak. I disconnected all my peripherals, and it still will not boot. I have now checked and I am not getting any juice to the 5V rail. I get 12V only. All my fans spin, and USB shows power, but nothing else works. Keyboard lights will not come on (even though they flash quickly on boot), hard drive will not spin now.

I used a voltmeter, and checked the 5V rail off of one the molex that plugs into the hard drive and there is nothing. I am also booting manually via J9 now. So i think my M2 is broken or somehting

**2k1Toaster** · 02-05-2007, 07:18 PM

How did you ever manage to get it to boot with no 5v?

I think because you overloaded it, and now it wont work.

Reread what wired posted. 140W peak, is ok iff (if and only if) each rail can supply enough. Meaning if you got 1 M2. And tried to run 160W of only 3.5" harddrives it would blow up and die taking you with it. Because 3.5" drives consume all the prescious electrons from the 12v rail for that monsterous platter spinner. It only sips from the 5v for the logic. So if you ran 12 amps off of the 12v rail, and 0 off the 5v, it is less than 160W. But too much on the 12v alone. The 12v can handle 8A I believe. P4's are like 3.5" harddrives. They will slaughter any 12v source you give them. That's why they make less than ideal CarPC's.

**Qwicker** · 02-05-2007, 07:39 PM

OK, well i took everything out of the car and brought it inside. I have ghetto rigged the M2 by splicing into a 12V wire from an AC PS.....yes i realize this is less than an ideal setup. I shorted the AC PS so it would turn on to supply the 12V to the M2. I then have the M2 hooked up to my carputer. Here is what I have found...

There is definitely 5V and 12V being supplied. Strangely enough the computer does not boot properly. Also, the Hard drive will not spin up when the IDE connector is attached. While the system is running, i remove the IDE cable, and presto, the HD turns on...very strange. I am currently unable to test the 3.3V because i have nothing to tap into. However it appears that the M2 is delivering power. I am really really at a loss of words. It worked fine yesterday!

Also, to answer some power consumption questions...I have a 1.8Ghz P4 on a mini-atx mobo with 1 3.5" HD, integrated 64mb graphics and wireless PCI network card. I have a keyboard and a touchscreen monitor which uses a usb port. Also, yesterday i had my cell phone and blue tooth device plugged into the USB ports for charging....but it all worked. I came outside this morning, and dead!

**2k1Toaster** · 02-05-2007, 07:44 PM

Things can work overloaded but only for so long...

And as for the IDE thing, usually HD's wait for the mobo to tell it to power on before they spin up. If no cable or a faulty cable or a loose cable is detected, they spin right up. Newer drives at least. This is so the drive can go to sleep when not needed and spin back up when it is needed. It is a mobo thing just to explain the weird factor with the HD. Not abnormal at all.

And using a desktop PSU to supply your M2 is actually a good idea and how most people do it inside.