M1-ATX woes

**Fusion-One** · 10-04-2005, 09:09 AM

New post is at the bottom.

My system is as follows:

1x 1.4ghz Celeron
1x PC Chips 791G Flex-ATX motherboard
1x 512mb PC2100
1x 7200rpm Seagate 0.35A 12v, 0.72A 5v

When I give the system pure (12.00v), it starts without a thought.. even with the 4 usb ports loaded: GPS, keyboard, mouse, external DVDrom. While building it i was beyond happy.

Now that I've mounted it in my car, it will not start if the car is not running (11.86v), and it will only start 1 out of 10 times if the car is running(14.4v). I've tried unplugging all usb devices, which makes no difference.. I bring it back inside, and put her on the 12v pure, and she starts no questions asked. I even removed the harddrive, and this increased the chance of it starting if the car was running to almost always, but still it will not start with 11.86 volts. I don't believe its my car electrical, either.. as I've had several invertor systems running off it in the past, have a brand new oversized altenator, and my amps have functioned flawlessly for the last year they've been installed.

Any ideas, suggestions or help is much appreciated.

-Jared

**neon_eddy** · 10-04-2005, 10:34 AM

that 7200 rpm drive isn't helping. although I feel your pain. I have one too, and I find sometimes mine doesn't like to boot, normally if I've had my interior lights on for a while or something, and when a PC starts up it pulls a lot of power, much more than normal running.

make sure your battery is good and charged, maybe a tank circut would help.

**Fusion-One** · 10-04-2005, 10:39 AM

Yeah.. I was thinking along the same lines.. and was thinking perhaps a good sized cap right before the M1 would make it happier.. but if I'm going to buy that, I might as well just get an opus. =P

To boot (oh look, a pun) the replacement chip for my M1-ATX causes the psu to not do anything, so I had to swap the original chip with the broken timings back in just for her to kick. :P

**neon_eddy** · 10-04-2005, 10:49 AM

talk to the manufacturer, I think yours might be defective.

**zvi** · 10-04-2005, 01:31 PM

the desription says: this PSU is good for VIA EPIA boards, may it can not handle 1,4 Ghz Celeron and your mobo?

**Fusion-One** · 10-04-2005, 02:54 PM

the description actually says it is suitable for celeron I II, and III processors.. but not AMD or P4 style systems. :P Which is exactly what I have, and at bare minimum, too.

I'll send em an email to see if what I'm experiencing is normal.. but I have a feeling it is. It functions so well running off 12.00v that I cant see there being anything wrong with it.. just once the voltage changes and the efficiency goes down.. everything turns to poo. :P

**andrewb** · 10-05-2005, 12:38 AM

Cannot guarrantee all motherboards types, sorry....
Try to reduce the 12V rail power consumption, if possible.

Celeron 1.4Ghz is using the 5V rail for V(core) step-down, so in theory the M1-ATX should work, sorry I don't know what is going on here, some boards are fussier than others at startup. Some on-board BUCK converterws tend draw insane amounts of current at startup.

You can RMA the unit, but most likely another M1-ATX will not help here...

An input capacitor will not help.

-Andrei

Originally Posted by Fusion-One

the description actually says it is suitable for celeron I II, and III processors.. but not AMD or P4 style systems. :P Which is exactly what I have, and at bare minimum, too.

I'll send em an email to see if what I'm experiencing is normal.. but I have a feeling it is. It functions so well running off 12.00v that I cant see there being anything wrong with it.. just once the voltage changes and the efficiency goes down.. everything turns to poo. :P

**Fusion-One** · 10-05-2005, 02:07 AM

Ya, I'm sure the unit is fine.. its just.. sooooo close to the edge. I have a little 1.5 amp pt5071 12v regulator here that I'm gonna use to power the 12v for the hardddrive.. hopefully that should jimmy fix her up for me.

-Jared

**Fusion-One** · 11-19-2005, 10:38 PM

Still having this totally sporadic problem, sometimes it starts, sometimes it doesn't... however, with testing of each line, I've found it isn't that the psu is being overwhelmed.. I've actually got a lot more headroom. With testing, I've found it ALWAYS starts if I manually short J8 on the M1-ATX.. so without a doubt, its the J6 connector signal/switch on my M1-atx that is causing the problem... the thing I can't figure out is why its happening so sporadically.. sometimes itll start no problems at all.. and the rest of the time it just makes the fans twitch..

Is it that the J6 isn't switching long enough.. or is it sending a logic level "Turn on" signal to the motherboard which it only understands sometimes? Is there anything I can do to fix this? I've searched like crazy, but all I found was that maybe my motherboard requires reversed logic from the J6?.. and there was no info.. just a vauge passing comment... any ideas?

**Fusion-One** · 11-19-2005, 10:51 PM

Something else worth mentioning.. often times, when the system doesn't start, and I switch the ignition power off, the computer will then start up until hardoff shuts it down... almost like it IS actualy working in reverse... any ideas on how I can fix this?