So, what did Zenith do to make their CRT's fail quicker?

[andy]

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[MRX37]

Originally Posted by ctc17

I just tested it out and it works but the picture is so dim I have to be in a totally dark room to see it.

Was that the problem with these or was it mostly guns shorting out?

I'd almost bet money you have a rebuilt Zenith CRT in there, probably from 1995 or 1996.

If it still has the original CRT in it I'd be surprised.

[freakaftr8]

Well I have a Dec 1983 25" Zenith Space command with "Space phone" that my uncle has sitting at my work. He has had it since new and used it since new! Just a few weeks ago he noticed that colors especially red wask over to the right. Green too, but not as bad. Im almost positive the CRT is getting tired. It drives the colors off with the contrast turned up.
It's sad that our proud company produced once probably the best CRT on the market, and this one in this set is no slouch (it's gotta have thousands of watching hours on it) to something that lasts 6 months...

[radiotvnut]

That '83 would probably respond well to rejuvenation with the right tester. It's amazing when the older tubes just last and last and the newer ones are doing good to last out the warranty. I just picked up a '58 Zenith B&W portable and the CRT is in great shape.

[radiotvnut]

I just did something you won't believe. I actually did a tube swap in a 25" '98 Zenith with a dead tube (red dead, green almost dead, blue good). I had some fun with the old tube before pulling it out. I cranked the filament voltage up to 12 volts (that's how high I had to go to get it to register "good"). When I did that and checked for shorts, the needle was going crazy on all guns. hitting the neck of the tube with a screwdriver handle was causing even more excitement with the shorts test. I was just about to rip out the chassis when I remembered there was a 25" Magnavox tube from the late '90's in an empty cabinet behind my shop waiting to be thrown out. The mounting ears on the Magnavox tube were a little higher than the ones on the Zenith tube; but, I was able to mount it without any problem. I never could get the purity right and ended up ripping out the rubber yoke wedges and shoving the yoke all the way up on the tube. Actually, the set that the Magnavox tube was in had been dropped; so, there may be some shodowmask damage to the Magnavox tube. At least it's watchable now and maybe I can find it a home. With that Magnavox tube installed, the TV is probably more reliable now than it was the day it left the factory.

[MRX37]

I wonder if you could just throw in any old CRT from another brand of TV made in the same era and have it work?

[radiotvnut]

I've done it many times with various brands of TV's over the years. As long as the tube is electrically the same and will mount in the cabinet, it will usually work.

[andy]

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