7" LCD screen color loss problem

vladilen · 10-02-2003, 07:05 PM

I have a DSCustoms 7" VGA touch screen installed in the dash. All worked great up until about 1 month ago. Now for no apparent reason the screen loses the red color every once in a while - the display gets a heavy cyan cast. After a while it will switch back to normal.

This behavior happens when the car is standing still, or driving ruling out the possibility of a bump causing a connection to become loose.

The periods of color vs. wrong color are not constant. They vary from a few minutes to a few days.

Any thoughts?

Enforcer · 10-03-2003, 04:28 AM

could be a dry joint, or an overheating component.

vladilen · 10-03-2003, 06:06 AM

Quote: Originally Posted by Enforcer

could be a dry joint, or an overheating component.

I'm not sure about the overheating - the color loss occasionally persists overnight and then goes away while driving. I assume that if a component was overheating the color would be fine in the morning when the car has been cool overnight and would act up during the drive.

As for the dry joint - completely possible, however it has been working for a month and has just now started to act up.

videodok · 10-03-2003, 06:16 AM

Quote: Originally Posted by vladilen

I'm not sure about the overheating - the color loss occasionally persists overnight and then goes away while driving. I assume that if a component was overheating the color would be fine in the morning when the car has been cool overnight and would act up during the drive.

As for the dry joint - completely possible, however it has been working for a month and has just now started to act up.

Is your colorloss instant or gradualy?

vladilen · 10-03-2003, 06:26 AM

Quote: Originally Posted by videodok

Is your colorloss instant or gradualy?

Instant. The return is also instant.

Pudge · 10-03-2003, 07:52 AM

viadilen, I get this on my home monitor every few months (sounds like the same problem). Try simply retightening all of your connections. Sounds cheasy, but it happens.

This is my understanding of why, it seems logical, but I haven't researched it... A computer outputs RGB, Red Green Blue, when a vga connection isn't all the way plugged in, or loose, or maybe the cord is damaged, it only sends parts of the signal. In your case, you are missing the Red. When the connection jiggles around, it works again. Again, I haven't done any research on this, but I do know that it has happened to me before, and tightening all of the connectors worked.

vladilen · 10-03-2003, 10:13 AM

Quote: Originally Posted by Pudge

viadilen, I get this on my home monitor every few months (sounds like the same problem). Try simply retightening all of your connections. Sounds cheasy, but it happens.

This is my understanding of why, it seems logical, but I haven't researched it... A computer outputs RGB, Red Green Blue, when a vga connection isn't all the way plugged in, or loose, or maybe the cord is damaged, it only sends parts of the signal. In your case, you are missing the Red. When the connection jiggles around, it works again. Again, I haven't done any research on this, but I do know that it has happened to me before, and tightening all of the connectors worked.

I've tried that. Even replaced the extension cable - no effect. I'll try to connect a KVM switch to it this weekend to see if amplifying the signal will help.

gork · 10-03-2003, 01:30 PM

This problem is likely due to the cable connector into the monitor. It's a fairly flaky hookup to be certain. See if jiggling it causes the red to come and go.. If so, see if you can do something about making it more secure.. Zipties and hotglue did it for me, though I never experienced a problem... I thought ahead

It is unlikely that the problem is with the LCD or controller as you'd experience something other than the loss of the red channel. This sort of thing indicates a problem with the RGBHV vga input.

vladilen · 10-03-2003, 02:11 PM

Quote: Originally Posted by gork

This problem is likely due to the cable connector into the monitor. It's a fairly flaky hookup to be certain. See if jiggling it causes the red to come and go.. If so, see if you can do something about making it more secure.. Zipties and hotglue did it for me, though I never experienced a problem... I thought ahead

It is unlikely that the problem is with the LCD or controller as you'd experience something other than the loss of the red channel. This sort of thing indicates a problem with the RGBHV vga input.

My connector is re-soldered and epoxied to the board since it came loose once already. I tried to drive over rough terrain to test the theory of a loose connector - logic being that a loose connection would be more evident when the truck is bouncing up and down, but no luck. The dash is a pain to take appart, so I'm trying to avoid doing that at all costs.

duffydawg · 10-04-2003, 02:42 AM

I would definitely try another cable. If you stabilized the connector on the screen and still having the problem, it must be the cable. If it's not one, it's got to be the other. good luck.