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trickyuno · 02-03-2006, 07:31 PM

Quote: Originally Posted by DarthTater

When in "dumb" mode the M2 will provide a constant 5V to the MB so that it can monitor the on/off switch - some MBs will also leave the USB ports on as well creating more drain on the battery. The M2 will NOT shut off due to low battery voltage in this mode. If you want to use the M2 as a switched device via the ACC line, you must set the jumpers for one of the power management schemes.

Also, if you are getting the +12V from the existing vehicle wiring, it may not support the current draw which could be causing your non-POST issue. Run a power line direct to the battery with a reasonable gauge of wire and it may solve your problems. Just don't forget to fuse the line within 12-18 inches of the battery or you risk a fire in the event of a short.

Yeah, the grounding thing is common. Hell, even your desktop PC shares the same ground plane across devices. If you pull the power cords on your PC and monitor leaving the VGA cable connected, you will find continuity between both devices through the ground prong on the plugs.

Hope this helped - good luck!

Ran +12v direct to battery but still no post, mb is good works on bench with desktop psu. Cant be insufficent 12 rail on M2 reduced to cpu, 512mb ram, graphics card and hard drive but still no post. Any ideas?

02-03-2006, 07:31 PM	#6
trickyuno Newbie Join Date: Dec 2005 Posts: 30	Quote: Originally Posted by DarthTater When in "dumb" mode the M2 will provide a constant 5V to the MB so that it can monitor the on/off switch - some MBs will also leave the USB ports on as well creating more drain on the battery. The M2 will NOT shut off due to low battery voltage in this mode. If you want to use the M2 as a switched device via the ACC line, you must set the jumpers for one of the power management schemes. Also, if you are getting the +12V from the existing vehicle wiring, it may not support the current draw which could be causing your non-POST issue. Run a power line direct to the battery with a reasonable gauge of wire and it may solve your problems. Just don't forget to fuse the line within 12-18 inches of the battery or you risk a fire in the event of a short. Yeah, the grounding thing is common. Hell, even your desktop PC shares the same ground plane across devices. If you pull the power cords on your PC and monitor leaving the VGA cable connected, you will find continuity between both devices through the ground prong on the plugs. Hope this helped - good luck! Ran +12v direct to battery but still no post, mb is good works on bench with desktop psu. Cant be insufficent 12 rail on M2 reduced to cpu, 512mb ram, graphics card and hard drive but still no post. Any ideas?