I am having problems with my m1-atx. When I have everything hooked up properly - that is 3 lines, ground, battery, and ignition signal - the computer does not turn on. Or, at least it is inconsistant, turning on maybe 5% of the time.
Ground is pulled from the frame. Bettery is a 10 gauge wire I ran directly from the battery. Ther is an inline fuse about 2 inches from the bettery terminal (I check the fuse - it is fine). Ignition signal is pulled from the cigarette lighter.
Everything was working fine for quite a while, then all of a sudden the PC stopped booting when I started the car. At first I thought it was a loose wire, so I traced every wire, and found nothing. Then I pulled out my volt meter, and thats where things got really wierd.
When the battery wire was connected and the car was running, the battery line would show 1-3 volts. If I disconnect the battery line, I would get 12v. Reconnect, and it drops to 1-3v. Then in the process of testing, when I reconnect the battery line, the pc would suddenly power up, and everything would be fine. But then when I turn off the car, and restart it, the pc would not start, and I would have the same voltage problems.
To test, I tried connecting the ignition wire and to both the power and ignitioin lines of the power supply (powering the unit with the cigarette lighter line). This works perfectly. Thepc powers up, and stays on. I can stop and start the car 100 times, and it consistently turn on. The down side of course is that the pc is abruptly powered down when I stop the car.
I know this sounds like a faulty battery line, but I can assure you, the line is connected straight to the bettery, the only break in the line is for the inline fuse, which I tested numerous times. the line is fine.
It seems like the power supply does not like having constant power. It powers up fine from the ignition line, and powers up ok if I disconnect the battery line and reconnect it.
For a while I thought I had a faulty power supply, but I resently got sent a new power supply, which was working fine for about 5 boots or so - all 5 boots were pretty close together - I was putting together a new case and doing testing. Then when I had everything all together and started the car the system started booting and then suddenly powered down. I did a quick voltage test on the battery line (while it was connected to the psu) and got 1volt. I disconnected the battery line, and hooked into the ignition line and the system booted right up.
So I am THOROUGHLY confused right now. has anybody else seen a similar problem, or know what else I can try ?
Any help is appreciated.