Shadows on Toshiba Rear Projection TV

My Toshiba (TP48e50) rear projection tv of about 6 years has developed shadows in low light conditions and with a blank screen I can see shadows across the screen. The picture looks ok in bright seens. Are my guns going bad? Or do I have clouded cooling fluid and it the fluid needs changing? Where can I find instructions on how to change the fluid?

 

Good Morning, bobfennessy:

I wouldn't imagine that the cooling fluid is the problem. It will last the life of the projection tube and should never need replacing. In the event of a cooling fluid leak, however, you can add to the reservoir.

In your case, it sounds like image retention. Have you been letting the kids play their video games using this unit? A set that has been subjected to prolonged periods of projecting the same image will have this problem. The image will "cook" itself into the phospher on the face of the projection tubes and will be evident in low brightness conditions.

In this case, the only fix is to replace the tubes. Considering the cost of replacement tubes, you will actually buy the set all over again. Better to consider a new unit.

Smokey

 

I don't think I have a problem with image retension. No games ever played on tv and it has only been used less then 4 hours per day. The shadows look more like grey clouds on peoples faces and on a blank screen it looks like wavey clouds on the screen. I have seen burnt in images and this doesn't look at all like that.

 

Good Morning, bobfennessy:

Interesting! Well, I wouldn't blame the cooling fluid and wouldn't think that dust on the lenses of the projection unit would cause the clouds.

Have you been inside the unit at all? This sounds like something between the projector and the screen. A dirty reflector unit perhaps?


Smokey

 

I took the screen off and behold there was an oily looking film and a few bugs inside the lens. I cleaned mirror and all of the optics and now I have a much brighter picture with no clouds or showdows.
Thanks very much for the assistance.

 

Scratch one up for the guys in the white hats! Glad you took a look and solved the problem.

Smokey

 

My Toshiba 48e50 large screen projection TV now has a foggy look and when there are low light scenes, the faces are looking like they have wisps of fog on them. I cleaned the lenses back in March and it looked pretty good then, but now it is getting worse again. I don't think it is dirty lenses again. Can anybody give me a clue as what to look for?

 

bobfennessy, Did you check to crt's for any greasy film on the lens? What did you use to clean the lens the last time?


Fred

 

bob, Also check the reflective path the screen and the inside of the screen itself.


Fred

 

I checked the light path all the way through, I think. I cleaned the path with 99% Isopropyl alcohol and lint free tissue, I will go back and check the path again and see if I missed anything.
If I have no video on the screen (grey screen) it looks like waves of fog accross the screen in a diagonal path. Thanks for all of the suggestions.