Riddled TV Repair Forum

Shock · Joined: 28 Jun 2010 Posts: 2 Location: Canada

This is my parents TV and they are a bit hesitant to throw it out. It's an older 50" Rear Projection CRT TV that has served them well.

One day, the picture suddenly became very dark with a bit of distortion at the top edge. The colors are all messed up with red & blue overpowering everything and the greens the most faded. It doesn't seem like there is any "white" being added to the picture that needs to balance it out as it's all really dark. It almost looks like a negative picture.

Any ideas what this could be? Is there a bulb or lamp that is burned out? I also hear you need to replace the coolant fluid in the color lamps sometimes. Could it be this?

What I can't figure out is why the picture from cable, DVD, AV in, etc. are all like this, but the menus are all fine and sharp and full color. If it was a color tube that was physically out or something was damaged, shouldn't everything on the TV be messed up or is the menu system projected by an alternate system?

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JTS1957 · Joined: 21 Jan 2009 Posts: 2394 Location: Far, Far Away

Shock · Joined: 28 Jun 2010 Posts: 2 Location: Canada

It is a Proscan 50700 from around 1998.

Here are more images of what the picture looks like. If the OSD is on different RGB pins of the IC, aren't both images projected from the same tubes? I haven't disassembled the TV yet to take a look at the physical tubes. I am moderately okay with basic electrical/electronic/mechanical things but I've never worked on a TV before and wouldn't know where to start.

Any ideas what the culprit behind this is and if it is worth fixing? Could it be as simply as coolant fluid replacement?