Newly built PC not powering up

**Hobart007** · 02-04-2007, 04:52 PM

Hi all,

I just finished building my carputer and am reasonably sure that the insides are all properly assembled as this is far from my first that I've assembled. My problem comes when I try to hook the PC to both an AC-DC converter (12V, 1A) and a car battery I get no power up. Instead I am getting a flash code on the diagnostic LED that corresponds with voltage that is out of normal voltage range or a faulty DC-DC power supply.

I have the correct connections for the positive and negative going to the PSU and have the ACC wire grounded to the case.

Any ideas on what I could be doing wrong? Could the PSU be faulty or am I missing something?

Thanks,

Jim

**2k1Toaster** · 02-04-2007, 04:58 PM

How are you powering this? You are using a 1A converter? There is you problem. You definately need something beefier. I have no idea what system you are using so I can't tell you how much, but I can tell you 1A is insufficient.

And a car battery? Are you using a DC-DC PSU or what?

You pretty much left out all the important details.

**DarquePervert** · 02-04-2007, 05:29 PM

Originally Posted by 2k1Toaster

You are using a 1A converter? There is you problem. You definately need something beefier.

**Hobart007** · 02-04-2007, 09:37 PM

I have a DC-DC PSU. I figured I would give it a shot with a car battery as well to (in theory) match the power it would get in a car. I just put a couple wire terminals on it and ran some 18 gauge wire to the appropriate places. (Positive went to the positive wires for the PSU and the negative to the negative - not sure where to put the AC wire so I have it grounded to the case) The DC-DC PSU is a 120W (Opus case #CCC-004 on mp3car.com store) and the PC itself is built on an Epia MII 12000 motherboard. With the exception of the drives (HDD & slim-DVD) nothing else is attached to it so the power consumption should be small. I just don't know how its not got the right power when its directly connected to a car battery for power to get things installed and tested before I go rip half the dash out of my G35 to get it in.

**2k1Toaster** · 02-04-2007, 09:44 PM

You connected the ACC wire to your cases ground?!

You must connect this wire to something that gives +12v when you want your carPC on. Basically for testing, tie it to the +!2v constant. For actual use, solder it to an "ignition" wire under your dash. One that is off when the car is off, and on when the car is on.

Also 18awg wire is too small. I would be scared. And where did you get your ground point and +12v constant point. Please don't say cigarette lighter...

**DarquePervert** · 02-04-2007, 09:47 PM

18awg is pushing it. I'm not certain 18awg wire is able to carry the load required for the PC. I suggest thicker (lower gage) wire.
ACC line needs to be 'hot' in order to trigger start up. The Opus manual is pretty clear about that. You can simulate teh ACC going 'hot' by connecting it to the positive terminal on teh battery.

[EDIT]Damn, Toaster!
We're both in a helpful mood tonight... Well, where it's warranted, anyway.

**Hobart007** · 02-04-2007, 10:06 PM

So thicker wire. I am going to give that a shot tomorrow afternoon after work as I am still too depressed by that football game I just watched. Not only were my Raiders not there but I think the Bears were asleep or something. Ugh. So would I need something thicker than 10 gauge or should that cut it?

Also Toaster, its not in the car yet, I am trying o get it up and running in the house on a car battery to get it all set up, tested, and to get the applications and my MP3 collection installed. I plan on attaching the wires directly to the battery where I can with the exception of the ACC when I put it in the car.

**DarquePervert** · 02-04-2007, 10:13 PM

10awg is more than adequate.

**2k1Toaster** · 02-04-2007, 10:13 PM

well to get it to boot up at all, you need the ACC wire to be "hot" as DP put it. SO if you are testing in the house, just tie the power and acc wire together. If the ACC wire is going nowhere, you will get no booting.

And 10awg is fine I guess. I am a fan of thicker wire because it makes me feel better to know this will work and can hold way more current than I will be drawing off of it rather than, this should work ok for this but only this. If you ever upgrade the computer and forget the wiring, that could be a boo-boo. But 10awg should be ok.

EDIT: DP wins this time!