60" Philips Magnavox Projection TV Red Screen
I bought a crappy old magnavox and rebuilt it. I had both of these issues.
Since your tv is old, the blur problem is probably caused by old coolant in one or more of the CRT lens couplers. Hopefully, the lenses are simply out of alignment, but no one has ever worked on the tv, then this is unlikely.
First, unscrew the back panel of the tv console (should be a bunch of 1/4" hex head screws). There will then be a large white panel at a 45 degree angle held in place by two tabs or maybe even screws. Remove it to see the CRTs. A quick check for the blurry problem is to look directly into the CRTs while the tv is off. DO NOT do it while they are on if you can help it, as it is not good for your eyes.
Shine a white LED flashlight down into each of the CRT's top lenses. Avoid classic incandescent light in this case, since you will be looking for the difference between white and yellow. I you see a white plate inside, good. If the inside looks yellow, and has floating things in it, then the coolant fluid inside is old and bad. You can replace this, but it is a VERY delicate task and MUST be done in certain steps to avoid ruining the electronic boards anywhere within splash zone or drip reach of the lens couplers. The coolant is a special blend available at most tv repair shops, but it's basically clear antifreeze (which you wont likely find in an automotive store).
For the color being off, it is most likely the gain on each CRT being out of whack. First, change all of the user settings (in the on screen menu) for image, color, sharpness, etc to the middle or default.
With the back panel off, somewhere near the bottom of the inside there will be a small black plastic box with wires coming out the sides. This box should have 6 knobs on the front of it (the face facing the rear of the tv); 2 rows of red, green, and blue knobs. These are the screen controls for FOCUS and GAIN. And they should already have some sort of label telling you so.
I placed a mirror in front of my tv so I could see the screen as I adjusted, but you might be able to see it somewhat by hanging a sheet over the front of the screen and looking at it from the inside.
There's a much more in depth method to do this that is described in the service manual (which you are likely to have seen by now; they are usually either stapled to the back of the tv or hanging somewhere inside and easy to see)
But basically, just turn the knobs gently around until the picture looks about right to you. (Remember, if you turn them all up super bright, the CRT will not last very long. Try to keep the knobs near the middle of their turn ability)
If you want to do a full out overhaul of the screen, you'll have to make a lot of adjustments with a bunch of little knobs (variable resistors, really) on the computer board inside. The service manual will tell you what each one corresponds to, but most of them will have a subtle label on the board.
Email me if you need any help
Apr 15, 2007 |
Philips Magnavox 51MP392H Rear Projection...