flip down tft going bad no color

I have 4 7" 16:9 flip down monitors in my minivan. Two of them seem to be going out as they are starting to only display the video in black and white. It seems to be a component going bad, as they will play in color for the first 5 minutes of so, then start flashing weird colors then only black and white. The picture quality is the same, just no more color. They have composite video inputs and are feed with video amplifier, I have tested each monitor with and without the video amp and the I believe that it it the monitor and not the amp or the source. I have an extra video amp and the results were the same. These cheap/inexpensive monitors made in China. I would appreciate any constructive comments. Thanks :)

What brand are the monitors?

Hi - The brand is called Innovatek from www.mp3playerstore.com.

Since my post, I have removed 2 of the 4 monitors from my minivan. I have bench tested both of them by leaving them on for days and playing a DVD movie with a spare Pyle DVD player. It seemed that when the monitors were operating for a "period" of time, maybe, 1/2 hour, the color would go away. But, the removed monitors appear to be okay. I even had one taken apart to expose the PC boards, I took a heat gun and heated the boards up. The monitor did not fail to produce the b&w effect.

But, out of the two in the van, the one that is most used by my 7 year old son, still goes b&w after 20 minutes, the other one does not. I think that this monitor has a real problem, where the others my have a wiring/connection issue. I need to take some time to rerun the power and video to each monitor.

The one that I believe that is failing, I will try to debug to the component level.

Thanks,

-rob

Well, after some on/off time trying to debug the problem, seems that all of my monitors are working properly and that I have a wiring problem. After removing two of the 4 monitors, I took the one that was failing the quickest, as all monitors would power up in color, then after a short period of time, 2 of the 4 would go to black & white.

I took the monitor apart and hooked up power on my work bench with a spare DVD player. I think took a heat gun and warmed up the PC boards. I was trying to speed up the process to get the monitor displaying black & white. This never happened on the bench and then I kept the DVD player on repeat and the monitor on all night and still no failure.

To make my long story short, I used upholstery pins (long stick pins) to hold my floormats in place. Seems that I pierced one or more of the monitor cables routed under the carpet. I am in the process in making a new, simplified harness for all 4 monitors.

Overall, do you like what you got with the Innovatek monitors?  I'm looking for decent (quality/price) 15-20" monitor (no DVD) for my truck.  Thanks.

With regards to teh Innovatek monitors, they are simliar to Pyle, Boss, and other brands made in China and other asian countries. These 7" are bright have good color.

rob_fed wrote:

---

I have 4 7" 16:9 flip down monitors in my minivan. Two of them seem to be going out as they are starting to only display the video in black and white. It seems to be a component going bad, as they will play in color for the first 5 minutes of so, then start flashing weird colors then only black and white. The picture quality is the same, just no more color. They have composite video inputs and are feed with video amplifier, I have tested each monitor with and without the video amp and the I believe that it it the monitor and not the amp or the source. I have an extra video amp and the results were the same. These cheap/inexpensive monitors made in China. I would appreciate any constructive comments. Thanks :)

---

Well, I thought I had the problem licked when I remade my wire harness to all four monitors. But on a long trip, they all went black and white again :(.   So, I think I have fixed them once again. I actually had two addition Pyle monitors that I adapted to the roof mount from the other monitors. But the Pyle's went black and white too.

So here is my theory. After opening up both the Pyle and Innovatek monitors, they both use the same video driver chip, TDA8361 or OM8361. I first suspected the NTSC color burst crystal. I actually replaced 3 of the 4 but no real fix happened. I suspected the crystal because I was able to get the color back by using the freeze spray on the crystal.

After inspecting the circuit boards, I noticed that there were a huge amount of small electrolytic capacitors. After freezing and re-heating (small butane torch, quick bursts), I isolated the same 100uf cap in all of the monitors. After during some research, surface mount electrolytic caps lose there ability of holding their respective charge if they are not used very much. But they can be reconditioned by applying 30v to the the cap with the current regulated with a 1000 ohm resistor. I had another circuit board with the same 100uf caps and unsoldered a few and conditioned them.

I then replaced the cap in one monitor and found that it did not lose it's color and remained normal for over an hour. After that, I replaced the other caps in the other monitors and left all the monitors and dvd player on over night (used a battery charger to keep the battery up). And everything seems to be fine.

The Pyle monitors were not used for over 1 year, and the other monitors were not used for a few months. They are all about 4 or 5 years old. I am not sure what the cap does in the circuit, but was able to identify the same one on different boards.

Hopefully, I can post some pics for the fix.

Thanks,

-rob