My In-Dash Car PC project

[direstraits71]

I'm enjoying reading your thread and may be able to contribute. I take it your PC has conventional ATX-type power supply that's powered off an inverter in the car? If you can't ever get it to lock up in the house, I'd say it can't be a software problem exclusively. Sounds like the only difference between inside and in the car is how you're powering the computer. Your power out of the inverter may be causing just enough noise to get through your computer power supply and causing bit errors which when occurring in the wrong place definitely will lock up a computer. Noise problems are usually inconsistent too which fits your situation.

The normal fix for noise on the 12 volt power is an iron core inductor (choke) between the battery/fuse and the 12 volt input to the device being powered. The size of the inductor depends on how bad the noise is, but it must be rated for the current you're trying to draw. The worse the noise the more inductance you will need.

Hope that helps.

[momanz]

That electrical noise comment reminded me of a problem i had with grounding on my car pc. It turned out that the pc ground was about at about 1V higher relative to the car chassis. I ended up installing a ground wire from one of the motherboard fasteners to the car chassis. Fortunately I didn't incur the wrath of the ground loop gods. Not sure why such a thing would start up all of a sudden for you, but it's easy to check for, just take a volt meter and measure between one of the motherboard screws and your car. If you do find that there is a reading, think very carefully on what you want to do next. I'd hate for you to connect a jumper wire inadvertently release the magic smoke...

A couple of other things to look at... check your heat sinks to make sure they're in contact with the chips they're cooling. swap out your power supply with one that you know is good. I've had desktops that had the same behavior as what you've described. The initial bootup of windows is quite energy intensive and if your supply is marginal or failing you'll see errors and lockups.

-m

[Dngrsone]

The inverter idea is a good one, at least for trying an alternative method for verifying the power supply idea. Since the inverter generates a pseudo sine wave for AC power, it will act as a filter. Direstraits has a good idea there, though-- a spark-suppressor type choke should filter out most noise on the DC line, if there is any. Momanz' ground issue is also a good thing to check out... grounding in cars can be pretty messy-- I had a chassis ground problem in a Ford that was entirely dependent upon a single 18ga wire that had corroded.

[momanz]

One more thing I thought of during my morning coffee. Check the electrolytic capacitors on your motherboard. There was a period of time where motherboard makers were using substandard caps in their products and that lead to no end of stability issues for people (myself included). What your looking for is bulging or leaking ones. Google any you'll find plenty of info on this as it was a pretty big problem a couple of years ago. The solution is to replace the caps yourself, not terribly difficult but requires some skill with a soldering iron or buy a new motherboard. While you're at it check your powersupply too.

-momanz

[mrbigh]

My 2 cents, if we talk about grounding, I never rely on "chassis " connections, if for an instance you take a look to the Prius electrical schematic and internal wiring, you will see a redundancy of chassis tie points all over, indicating that the ground potential of "chassis" is unreliable.
Since all my electrical additions in my 2004, including a Carputer in 2006, my electrical distribution consist of a very flexible heavy 4 ga positive lead and a sister 4ga ground wire , from the battery to 2 distribution blocks under the passenger seat, providing juice to some gear, never connected to "chassis" crap.
Next I will look into your internal upgraded power supply, these are prone to electrical surges and certain voltages (3.3V and lower mainly) do crash momentarily, hanging your CPU.

[tundrwd]

Originally Posted by TheForce

I have the +12v hooked directly to the battery. The negative is hooked in on part of the chassis near the battery.

And does that go through a regulator? i.e you have it hooked up to +12V, and before it hits your mobo - is it going through a regulator?

If not - you've got a real problem, and are supplying too much voltage to the system. Normally, when a battery charges, the charging circuitry supplies +14-15V, too much for an unregulated circuit. You may also be seeing voltage spikes and momentary brownouts, as you power on/off various things in the vehicle.

If it IS regulated, then I'd say you'd have to pass it through a pretty good sized electrolytic capacitor, to suppress the noise generated by all the various vehicle components, that are being fed into your system.

Either that, or get a specific power supply made to supply an ATX mobo, that runs off of 12VDC. This may be the better route to go, in the long run.

[TheForce]

The 12v is going to an Opus car PC power supply designed for car PC use.

[TheForce]

Tuesday I ran some tests but because it was near 50F out side I dont know if I can trust the results.

I ran the computer normally for an hour. When I got out side after the hour it had locked up. I then turned off the PC and waited an hour for the PC to cool down. Next I booted into safe mode. I let it run for an hour and it was still playing video when I check on it. I then turned off the PC and let it cool for an hour. Next I ran the PC normally and it did not lock up after it ran for an hour. I think it ran OK because of the warm temperature out side and the PC may have still been warm.

Today since it was going to be near freezing all day I decided to only do a safe mode test on my way to work and on my way back. It did not lock up at all. If I was to run it normally in these temperatures it would have locked up in about 5 minutes.

So how would I diagnose this one?

Computer locks up when temps are below 50F
Computer does not lock up in safe mode when temps are below 50F
Computer does not lock up when its warm.

The only thing I can think of is its a combination of hardware and software issue. But what hardware / software combo would cause the PC to lock up when its cold?

[tundrwd]

This one may be tough. I assume by "safe mode" you are talking about Windoze safe mode?

This is apparently not a heat problem (normally, I'd say it's bad memory, but since it works fine when warm...). Since it does not show itself when running in safe mode, you need to figure out what's loaded/configured when in safe mode, and not, then start the process of elimination.

• Is your screen res the same in safe mode and not?
• Are you in "networked" safe mode or not?
• How about just unloading the various drivers, etc. (network, sound, etc), and then ignoring the "found new hardware" whining and see what's going if it still locks up.
• Also - have you made sure you have the latest drivers, especially display drivers? Historically, this is the cause of the majority of Windoze lock-ups.

[Dngrsone]

Originally Posted by tundrwd

normally, I'd say it's bad memory, but since it works fine when warm...

Actually, that is a good suggestion. Force, try running memtest86+ for a good six hours or so. If you get any errors, then you likely do have a hidden RAM issue.