Rca Color Problem

squigglyrulez · 01-14-2003, 09:33 AM

My display is clear and readable, with color, when the engine is

off and even when the car runs for a while. But after about 5

minutes of the engine running I loose color completely. I turn the

engine off and I get wavy lines of color. After waiting a while

longer the color finally comes back. I have tried the computer in

the house with a regular TV with no problems.

I also have an external camera wired up to the monitor and use a

video selector between this and the computer display. I have

tried plugging the RCA from the computer directly to the screen

but this doesnt work. The computer display always has this

problem, but when I switch to the camera the color is fine. So I'm

thinking it's not the display. I am using shielded RCA cables for

both input sources. I have a ground to the PSU that comes from

the cigarette lighter ground ( I didnt want to drill a hole in the

trunk). That PSU ground clears up the screen but still no color fix.

PLEASE HELP!!

AVGeek · 01-15-2003, 10:03 AM

Based on your description, you either have a faulty video output on your computer, or a bad cable from the computer to the switchbox (I am assuming you used the same cable when you bypassed the switchbox). Try using a known good cable (the one your camera is connected to) with the computer. If the problem persist, its the computer. If the problem is gone, plug the camera into the suspect cable, and see if the problem is there (it should be).

Dexter172 · 01-15-2003, 04:27 PM

It could be the alternator is not supplying enough power or some static noise in the video cable.

squigglyrulez · 01-15-2003, 05:07 PM

I bought a new cable and still have the same problem. I'm using a 300w inverter. I can plug dvd player and vhs player with no problems on the screen. I even tried running the computer video through that too, but doesnt work. I dont think it is a hardware problem because the computer works indoors fine.

MP3DUB · 01-16-2003, 03:30 PM

Me not being an electrical guru in the least, it sounds like with the car running, chassis builds up an electrical charge with the engine (alternator) running, so you might have a bad ground some where in the cars elec system, or you might need to ground it to the ground with those dragging strip things.

squigglyrulez · 01-16-2003, 05:24 PM

I also tried wiring the LCD directly to the computer PSU and the screen is great but it still just snaps to black and white before your eyes while driving about 10 minutes or so.

squigglyrulez · 01-21-2003, 06:55 AM

I used tv tool to change the color scheme of the frequency. The setting is -200. This fixes the color when tvtool is running but when it is off it changes back to black and white. I am happy with the tvtool fix, but does anyone know why the color still just disappears?

phil.45 · 01-21-2003, 08:43 AM

Your video card is outputting a poor signal which the TV is having trouble holding on to. What you finding is that when its showing a colour display, the TV is actually on the aboslute borderline, and with the engine running it tips it just over the edge. Its easier to decode a luminance signal than the chrome signal, hence B&W. I had this exact problem way back with a VGA>Composite convertor, and on one TV it would go to B&W after a few minutes, then eventually lose sync altogether. The tolerances of the TV components play a part in the sensitivity.

You can simulate a similar type of thing (although its an RF signal, the principles of the actual demodulated signal apply) by detuning your home TV slightly whilst watching a standard TV broadcast. Notice how it becomes B&W long before the picture is unwatchable.

Solution, get a different TV out card for your PC.

squigglyrulez · 01-21-2003, 08:44 PM

I appreciate the info. It really makes sense. I dont have the $$ to buy a new card. I paid only 20 bucks for it anyway, its a TNT 16meg card. For now I will just keep using TVTool. It seems to work for a long time.

THANKS phil45!!!!