How hard is it to get a replacement screen for a projection set?

[Rod Beauvex]

The thrift store has a JC penny set for cheap, but the screen has a huge gash in it. Is it possible to buy those sheets of plastic and have it cut to size?

[freakaftr8]

I know that the way the lens is created, it uses a certain design that has these grooves in the screen. Regular plastic won't work.

[joemama99]

I have replaced those screens with screens from junked sets I found on the side of the road.I dont think you would find an exact replacement.

[andy]

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[radiotvnut]

I agree that it would be best to find a screen from a junk set and cut it down to size. I don't think JC Penny has sold electronics under their own brand name in over 20 years; so, it would probably be difficult to find an OEM screen for it, anyway. And, I'd make sure the set was otherwise healthy before bothering with the screen.

[freakaftr8]

Yeah, those CRT's after heavy useage, or just the gel generally gets nasty. Especially the blue CRT. I agree with the other guys. Get a good flashlight and look down into the lenses and see if there is screen burn on the phosphers and the gel if it looks milky. It should be clear.

Power it up too and see if all the guns work. Look into the lenses with some sunglasses and see the raster image all the CRT's are putting out. Should be clear and really bright. Thats ho w I can tell anyway.

[old_tv_nut]

Agree - you need to use a similar junker screen, not a general purpose frosted plastic. The screens for these sets have prismatic elements to bend the light (by total internal reflection) from a steep angle behind the screen to horizontal rays out in front for viewing.

[radiotvnut]

Originally Posted by freakaftr8

Yeah, those CRT's after heavy useage, or just the gel generally gets nasty. Especially the blue CRT. I agree with the other guys. Get a good flashlight and look down into the lenses and see if there is screen burn on the phosphers and the gel if it looks milky. It should be clear.

Power it up too and see if all the guns work. Look into the lenses with some sunglasses and see the raster image all the CRT's are putting out. Should be clear and really bright. Thats ho w I can tell anyway.

It seems like that every big screen TV that I see that's over 10-15 years old either has a cloudy lense or weak CRT or both. About 5 years ago, a friend of mine had a mid '80's Magnavox big screen that was so dark to the point where you had to be in a dark room to see it. One night, lightning lowered the boom on it and he bought a Toshiba projection TV to replace it. Even though flat panel TV's are much lighter and have come down in price, I still get a lot of calls to repair the old style projection TV's. I used to fix a few; but, they started becoming more of a headache than I wanted; so, I stopped taking them in all together. What cinched it for me was an RCA PTK179 chassis set that I fixed, sold, and almost became married to it. I also had an older RCA PTK169 that I kept up for an old lady and it got to the point where it liked to eat HOT's every 6 months. If I wanted a large screen, I'd have to break my "no LCD/no plasma" rule.

[kx250rider]

I'd forget it. Unless you happen to find one on the same exact TV, you're in for a lot of work or $ to get a new correct one. Some are two-piece, and others are one-piece. The outside is a lenticular lens, and the inside is a fresnel diffuser. The fresnel is millions of concentric grooves, which need to be centered. In other words, if you get one too big, you have to cut precise even amounts off all 4 sides. Likelihood of cracking = about 98%

Charles

[John Marinello]

I replaced a screen in a 48" set once. If you find a replacement screen that is larger, you will have to cut it down correctly, because there are 2 lenses.
The outer lens is the lenticular, and can be cut from 2 sides. The inner lens is the fresnel, and must be cut from 4 sides to keep it centered. I didn't consider it hard to cut. I just used a sharp utility knife & a straight edge. The outer lens you'll be able to cut through easily, because it's quite thin. The inner one is much thicker, and will need to be scored several times, then you can just snap it in two. If you try to use frosted plastic, as an example, you will have the 3 bright RGB spots in the picture from the CRTs.