Power Drain or something else?

nolatron · 11-21-2005, 08:56 AM

Hi guys,

Ran into an issue with me carPC and wanted to see what others think could be happening here.

Below is a quick drawing of my setup.
VoomPC with MII 12000 mother board, M1-ATX PSU, and DigitalWW in-dash housing with a lilliput 7": touchscreen installed.

The On/Off Switch on the battery line to the LCD is to totally kill power to the screen. The switch is ON for the following of course.

Basically what's happening is when I have my engine running and turn on the LCD screen (video is on, LED is Green), the fan on the motherboard starts squeeling. Turn the LCD to stand-by (Video off, LED is RED), no squeel. I think it's squeeling because it's loosing power maybe.

Also, if I turn the car to only ACC ON (engine itself off), it never makes the noise.

So I'm not sure if this is a power drain issue on the carPC with the engine running or maybe some interference from something or even a possible bad ground.

Previously the carPC was in the back of my Mazda3, and so the ground point was right there. For the moment, I just ran the ground wire from the front seat to the back till I can find a new ground point (guess I could use the battery now).

I unplugged all my USB devices and it still occured.

I'll go out and find a new ground point, see if that changes anything, but I wanted to mainly get some feedback. See if anyone else has come across this.

Grey · 11-21-2005, 09:33 AM

Based on the information provided, I would say you definately have a bad ground. try terminating your ground in as short a run as possible. That should fix it.

nolatron · 11-21-2005, 09:41 AM

Quote: Originally Posted by Grey

Based on the information provided, I would say you definately have a bad ground. try terminating your ground in as short a run as possible. That should fix it.

I'm on my way to the garage right now

nolatron · 11-21-2005, 10:46 AM

Well, I moved the ground point to about ft away from the PC but no change. I forgot to put on the image that inbetween the battery and the on/off switch for the LCD is the lilliput egg.

I'm heading back out now to plug the + & - power line to the LCD direct to a plug on the M1-atx. My previous setup had the lilliput hooked directly to my old OPUS PSU in the back. So we'll see how this goes.

nolatron · 11-21-2005, 10:47 AM

Well, looks that was the problem, the lilliput inverter 'egg'.

Once I got the power connected direct the M1, no more squeal. Yay.