Results 1 to 6 of 6

Thread: Carputer Monitor Flickers.. Some type of noice / interference?

  1. #1
    Constant Bitrate
    Join Date
    Apr 2007
    Posts
    114

    Carputer Monitor Flickers.. Some type of noice / interference?

    I need some suggestions as to what could be causing my LCD Monitor to randomly blink on/off for a second. I have a 10.4" Shark (samsung lcd) touchscreen that I molded into my dash bezel. It worked great for about a year with no issues at all, now while driving around, randomly, the screen will just "blink" or cut off and then back on real quick. Its like the power goes on and then off because the monitor even displays the input icon showing that vga is connected like when you first turn the screen on or change inputs. It does this randomly, sometimes many times in a row, sometimes just once or twice while driving across town. I am using a Jetway mini-itx motherboard with onboard video and a M2-ATX power supply.

    First off a few notes: It's not a loose wire. All my wires are soldered and have been tipple checked. The problem occurs even while sitting still at a stop light and not in motion at all, but also seems to occur more frequently when I am accelerating or taking off. My alternator is a new 200watt alternator and puts out steady clean power. Also, I have other things in my center console with the carputer motherboard such as a wireless switchbox and a wired switchbox for my air-ride suspension that I have on the truck. Also, this random blink problem only occurs when the truck is running and it does not seem to occur on the monitors other input such as the composite video cable coming from my dvd player thus making me believe it's not a power cable issue. Now, when I use my wired switch box to adjust the air-ride on the truck (to open and close the air valves) that usually will immediately cause the screen to blink and always has, even before the random blink problem started. So there is some type of interference that I would like to eliminate as well, but I have now idea how too and don't think it's causing the random blink problem because the random blink occurs when I am not using the switch box in any way. Also, the carputer and my switchboxes are running off a direct power cable from the battery and are grounded to the body of the truck through the bolts that hold in the center console.

    What I have tried:Originally I had the power and ground for the LCD running directly off the M2-ATX power supply. I figured that maybe there was some type of power issue there so I ran a power/ground cable set directly from the batter to the monitor and put it on a relay so it would turn on/off with the carputer. This didn't help the blink problem at all. Originally I also had the power wires crimped, I went back and soldered them all to eliminate a loose connection. I also thought there could be a power/monitor cable interference issue so I went back and ran my monitor cable/audio cables down once side of my console and ran all my power cables down the other side of the console, this didn't help either and I still get some interference on my monitor cable (some faint horizontal lines). I am thinking that maybe it's some type of ground interference with the carputer/motherboard that somehow affects the vga output on the motherboard. Is there a way I can sort of "clean" the power before it gets to the carputer motherboard or make sure now feedback is coming from other stuff on the truck through the ground? I have heard of ground-loop isolators but am not sure how they work, where to get them, or exactly what they do.

    So if anyone could help me out with some suggestions here that would be awesome because I am about at witts end here with this thing!
    - Mike

  2. #2
    Newbie
    Join Date
    Dec 2008
    Posts
    37
    Have you checked the power to the monitor with a multimeter? Sounds like you are having a voltage drop. That monitor's working power is 11.5 to 13v DC. It could be a slight voltage drop below 11.5v that's causing it to shutoff.

  3. #3
    Constant Bitrate
    Join Date
    Apr 2007
    Posts
    114
    Quote Originally Posted by flnole78 View Post
    Have you checked the power to the monitor with a multimeter? Sounds like you are having a voltage drop. That monitor's working power is 11.5 to 13v DC. It could be a slight voltage drop below 11.5v that's causing it to shutoff.
    Yep, voltage to the monitor is pretty constant and well within specs at all times. I have had it running off direct battery power and off direct pc power supply 12v power and it has the same problem on both. It doesn't have the problem playing DVD movies from the composite video input of my DVD head unit though. The problem is somewhere in the video signal it seems. Over the weekend I tried another video card and the issue persists. I have a tripple shielded monitor cable with ferrites coming in the mail tomorrow, I will give that a shot, maybe it is interference?

  4. #4
    Newbie
    Join Date
    Dec 2008
    Posts
    37
    Any word on this? Since power doesn't seem to be the issue I am like you and leaning toward the cable being the problem since the monitor turns on and off when a signal is present.

  5. #5
    Constant Bitrate
    Join Date
    Apr 2007
    Posts
    114
    Quote Originally Posted by flnole78 View Post
    Any word on this? Since power doesn't seem to be the issue I am like you and leaning toward the cable being the problem since the monitor turns on and off when a signal is present.
    I am thinking it may be vga cable as well for a few reasons
    1. The monitor does not flicker when playing dvds from my dvd head unit (composite input). It does flicker when i hit the switches for the air ride still, but that is the only time, no random times. I can understand the switchbox flicker being some type of feedback
    2. I have changed everything else, power source, video card, still the same issue

    I bought a nice new Tripple shielded vga cable with ferrits from monoprice, i will put that in this weekend and see how that turns out.. i will let you guys know!
    - Mike

  6. #6
    Constant Bitrate
    Join Date
    Apr 2007
    Posts
    114
    Well, problem solved by simply installing a new high quality VGA cable from monoprice.
    I have no idea what is wrong with my old VGA cable, it worked fine for a year, but I am just happy the issue is solved! I would have tried a new monitor cable sooner, but it's a huge pain to re-run that cable (had to take apart 1/2 the truck's interior) and I was really thinking it was a power issue initially. I'm just glad it wasn't a problem with the screen!
    - Mike

Similar Threads

  1. 04 Honda Civic Type R
    By spaced_chris in forum Show off your project
    Replies: 19
    Last Post: 04-04-2008, 12:42 AM
  2. 99 Acura TL carputer project pics
    By Darkshear in forum Show off your project
    Replies: 15
    Last Post: 08-23-2007, 01:14 AM
  3. Replies: 6
    Last Post: 03-20-2007, 11:16 PM
  4. carputer install: I dare you...
    By Cat Monkey in forum General MP3Car Discussion
    Replies: 42
    Last Post: 01-27-2005, 06:34 PM
  5. My Weekend of carputer hell!
    By Sonicxtacy02 in forum General Hardware Discussion
    Replies: 10
    Last Post: 01-05-2005, 09:19 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •