ITPS Shutdown Problem

**digifreak** · 01-13-2005, 12:54 PM

I installed my PC into my truck yesterday and breathed a sigh of relief when it powered up and booted properly. I played around with it for a couple minutes and turned my truck off. When I turned the truck off, the PC shut down instantly, with no delay. It didn't go into shutdown, didn't have the 45 second delay like it is supposed to, just turned off.
Has anyone else experienced this? I searched through google to see if anyone else had issues like this, but didn't see anything. All that I could find was people having issues with startups, voltage issues and problems with the PC staying up when the vehicle is on.
I took the PC back into my house and opened it up to check my wiring and everything was set as it's supposed to be according to the diagram that came with the ITPS.

-Red wire to constant 12V (ran it to the battery with a 10a fuse installed)
-White wire to Accessory
-Black to ground
-ITPS Power switch is hooked up to the Power switch jumper on the mobo
-Out cable from ITPS is hooked up to the supply on the Morex 80w PSU

Is the ITPS bad? I don't know. This is my first car PC experience, so I don't really have anything to reference this to, besides what I read here on the messageboards.
Just for information purposes, I'm running an Epia M10000 mobo, and a WD 2.5" 40 GB hard drive, and a panasonic slimline dvd/cdrw drive.
Thanks in advance

**tbird2340** · 01-13-2005, 01:18 PM

Actually, unless they changed the manual since I got mine..

The red wire isn't the constant like one would think.. THe red wire is the switched ignition wire.

The white is the constant 12V.

I'm not sure if that would make it shut down instantly but you might want to change it..

**MikeH** · 01-13-2005, 03:02 PM

The ITPS needs 13.4V at its input so that it can provide +12V at its output. If your engine is off your IPTS is only getting +12V or less. Its output will be about 10.6V, which means your CarPC will not continue working.

**tbird2340** · 01-13-2005, 03:07 PM

But his CarPC is running fine.. He just said it's shutting off instantly when he turns his vehicle off.. It's not giving him the 45 seconds to do a soft shut down.

**SAScooby** · 01-13-2005, 03:19 PM

its the red wire/white wire switch

**MikeH** · 01-13-2005, 03:19 PM

That's because when he turns off his engine the input to the ITPS drops to +12V, which means the ITPS output then drops to 10.6V, which means his CarPC chokes... The ITPS (regulator) is not designed to work while your engine is off, and therefore can't give you a proper shutdown......! The design logic behind the ITPS is a bit baffeling.

**digifreak** · 01-13-2005, 04:26 PM

Ok, I see what you guys are saying. Either I have the red and white wire switched, or the PSU is dumping due to low voltage after the vehicle is turned off. I'll try switching the red and white when I get home and see where that leaves me. If the wire switching shows no improvement, I'll look in to upgrading to an Opus PSU.
Thanks

**MikeH** · 01-13-2005, 05:32 PM

I'll look in to upgrading to an Opus PSU.

Well....not so fast there young man....

Opus is not always the automatic answer. If your case already has a DC-DC psu inside (it must since you are using an ITPS), why don't you look into a CarNetix P1260 or P1280(sold here in the MP3Car store)? Don't throw away something you've already bought. If all you are running is a M10k, laptop HDD, slim DVD/CD drive, and a handful of USB devices, the P1260 or P1280 is probably a good fit for you.

Just my "unbiased" view...

**digifreak** · 01-14-2005, 09:29 PM

Thanks for the info MikeH. I'll have to look into that if swapping the wires doesn't work out. It's gonna have to wait for a little while to give it a shot though, I'm heading out tomorrow for 6-8 weeks to go to Guam. I'll be helping to get the USS San Francisco repaired enough to make it back to Pearl Harbor for more extensive repairs. Some of you may have seen some pictures of it on the internet or the news.
I'll get to look forward to finishing my truck pc while I'm there. Thanks for the help on my setup so far guys.