M2-ATX power problem

**VegasGuy** · 06-23-2009, 06:24 PM

I have a Mo-Co-So PC with the 160wt M2-ATX PSU. Constant is direct from battery, ground to chassis and IGN via a switch off ACC.

Everything worked great up to a couple of days ago. Now, when I turn of the ignition, the PC shuts down immediately. The timer settings are default.

The PC will not restart until I disconnect the power plug and then reconnect and start the engine. Once the PC (and car) is running, setting the IGN swich off will cause the PC to do a graceful restart.

is it possible the battery is not producing enough voltage (below the 11 volt min) across the constant line to power the PSU/PC? Since the PSU can "see" the IGN line and react when the car is running, the battery seems like the most likely suspect.

Thoughts?

VegasGuy

**DarquePervert** · 06-23-2009, 07:32 PM

Have you measured voltage on your constant 12v line and your ignition-controlled line both with the ignition on and ignition off?

Something isn't right with the voltage, I'm guessing.

A flat battery could be the culprit. Measuring the voltage will tell you if that is the case.

**Deric** · 06-23-2009, 08:09 PM

Can't help your problem but nice avatar

**VegasGuy** · 06-23-2009, 09:02 PM

<Deric> Great minds think alike...darn that Gravatar!

I just measured voltage on the battery and at the PSU constant source...12V+ at both ends. Now I'm depressed...bad PSU?

**2k1Toaster** · 06-23-2009, 09:21 PM

Originally Posted by VegasGuy

<Deric> Great minds think alike...darn that Gravatar!

I just measured voltage on the battery and at the PSU constant source...12V+ at both ends. Now I'm depressed...bad PSU?

Need when the car is on, and when the car is off.

**VegasGuy** · 06-23-2009, 10:06 PM

Okay, here's what I see.

1. Voltage on Constant measured at the PSU connector (car off) - 12v+
2. Voltage on Constant (car on) - 12v+
3. Voltage on IGN (car off) - 0v
4. Voltage on IGN (car on) - 12v+
5. Bios set to "Last State" on power failure
6. Win7 power settings to "balanced" - this is the default and has been working.

7. When I unplug and replug the unit with ACC on or engine started, PC starts normally.
8. Cycling the IGN toggle causes the PC to reboot - expected and desired behavior
9. Stopping the engine but leaving the ACC on - PC continues to operate.
10. Stopping the engine and going all the wat to off - PC stops immediately - no shutdown control at all and the PC will not restart unless the power plug is removed and re-inserted.

batter up.....

**2k1Toaster** · 06-23-2009, 10:15 PM

Is this a real M2 in there? Your problem sounds like a firmware problem I read about a while back on the chinese knock offs. How many mounting points does your M2 have on it? 2 or 4?

**VegasGuy** · 06-23-2009, 10:47 PM

Without pulling it out of the case, I can't say, although its very well mounted so I suspect 4. Its the one sold with the MCS Gen IV barebones system.

Link to specs:M2-ATX Specs