View Full Version : Intermittent problem with a newer Zenith TV


Cleve
01-03-2005, 04:26 PM
I don't know if it's 'heresy' to ask questions about newer sets here, but I have a 1994 Zenith 35" tube tv with the AVI system for my Home Theatre that I've owned since new. About a year and a half ago, it started doing an odd thing. Sometimes, after the TV has been on for a minute or two, the picture will become very reddish purple in tint. At first, I could cure this by turning the set on and off a couple times. Then it got more persistent - requiring the channels to be changed up and down repeatedly. Something about the 'shock' of changing channels will finally cause the screen to blossom a brillant opaque fluorescent green, and then the bloom disappears and the picture returns to normal.

The funny thing is... it comes and goes since it started. The problem went away for 4 or 5 months, then resurfaced, and was persistent. Then about a month to month and a half ago, it stopped happening and the picture has been fine.

Does this sound like something worth fixing if it becomes permanent, or should I junk the TV and buy a new one? Thanx.


Jim

wa2ise
01-03-2005, 05:00 PM
If you are comfortable taking the back of the TV (and know your way around high voltage electronics), chack that the connection between the CRT pins and the socket (likely there's a small circuit board with socket at the end of the CRT neck) are still good. Gently unplug and replug in the socket (check that there's no glue or such holding it). Don't force it, you don't want to break a CRT (wear googles and other personal protection just in case). Other connectors may need to be unplugged and replugged in. What this does is remove any corrosion inside the points of contact inside the connectors.

Other possibilities are bad solder joints. Check that board on the CRT neck, and other points where there is decoded RGB video.

At this point you might start shopping for a new TV....

rca2000
01-03-2005, 05:39 PM
The RGB out. transistors, in particular, probably need resoldering. these transistors are on heat sinks. CCheck o them. Also, there are several resistors, that may need resoldering, too. Check the crt board carefully.

kc8adu
01-03-2005, 07:01 PM
had one in the other day with similar issues.
its crt was marginal and bumping the g2 a bit fixed it.
the color shifting is the akb system trying to balance the greyscale automaticly.

Eric H
01-03-2005, 08:29 PM
Wasn't 94 one of the years Zenith was having CRT problems?
This could be an intermittent short in the guns causing this problem.
Sometimes GENTLY tapping on the neck of the tube with a plastic screwdriver handle will cause the problem to show up.

heathkit tv
01-03-2005, 10:17 PM
I was thinking the same thing as Eric.....this is a Goldstar built set with CRTs that have worse reliability than a 20 year old Yugo. Unless it turns out to be a easy fix, toss it and just be glad that you got 10 years out of that it......that's about 9 years and 6 months more than usual.

Gimme a pre 80's Zenith any day.

Anthony (AKA Disco Zenith Boy)

andy
01-04-2005, 12:33 PM
I think Zenith bought their 32" and 35" CRTs from another company. It doesn't eliminate the possibility of a CRT short, but this CRT should be no worse than other 35" TVs of the time. It probably has a Thomson CRT in it. As long as it doesn't have 1101 as the EIA number, it should be fine.

kc8adu
01-04-2005, 09:36 PM
btw the 35" tubes i have seen in zeniths were relabeled toshibas.

Cleve
01-04-2005, 10:53 PM
Guys;

Thanks for all the info and advice - I'd heard about Zenith's sagging quality - of course, I made this purchase in my pre-internet days... I've since read online that 90's era Zenith tv's are poopy kaka. However, I must say that I thought this set had a superb picture, in comparing it to other 35" models on the sales floor of the now defunct Sun TV - that was why i bought it.

My plan is, next fall, to buy some type of backlit LCD TV. I just didn't want, nor can I really afford, to spend the money right now for an expensive replacement tv. I'll try some of the suggestions mentioned here, if the problem reoccurs or gets worse.