View Full Version : 1994 27 inch Zenith Yeah, it's got a weak CRT.


MRX37
04-08-2009, 08:56 PM
The picture's still surprisingly bright enough, but it's tinted blue. Adjusting the color drive controls on the CRT neck board made things better, but it's still tinted, and the blue drive is as low as it will go, and red and green are up pretty high, too much higher and really bad color bleeding will result.

Heh, I wonder if the CRT in that 1994 Sanyo I have is compatable...?

PS: according to a sticker, the CRT is from February of 1996. Must mean it was replaced. Gee, I wonder why.......

radiotvnut
04-08-2009, 09:25 PM
A68ACT00X, correct? You could probably fit another 27" tube in there; but, you might have to play with the mounting. If you could find a mid to late '80's 27" Zenith console, they usually have the same tube and they will stand a better chance of being good. Otherwise, I'd get this one to look as good as I could, sell it for a few $, and stress that it's an "as-is" sale. Another thing you have to worry about is the tube shorting and taking out the power supply; and, those '94 models were the worst for doing that.

MRX37
04-08-2009, 09:31 PM
The CRT was replaced in february of 1996. It's a CA68AGD01X

No hope of getting ahold of an 80's Zenith, but i did manage to acheive a decent white point by turning the blue drive all the way down, and the red and green drive all the way up. No real color bleeding with the color set half way... so I think i'm going to try and sell it. Normally I wouldn't try selling such a piece of junk, but I need the money.

Plus I haven't the faintest clue how to swap a CRT... and too scared to try it.

Dr FET
04-08-2009, 09:39 PM
The picture's still surprisingly bright enough, but it's tinted blue. Adjusting the color drive controls on the CRT neck board made things better, but it's still tinted, and the blue drive is as low as it will go, and red and green are up pretty high, too much higher and really bad color bleeding will result.

Heh, I wonder if the CRT in that 1994 Sanyo I have is compatable...?

PS: according to a sticker, the CRT is from February of 1996. Must mean it was replaced. Gee, I wonder why.......

Have you checked the Blue drive circuit, more likely one of the caps in this circuit has gone bad and is holding the intermediate drive stage full on.
Regards...Rich

MRX37
04-08-2009, 09:52 PM
I did actually check the caps in the area. They're good. Plus the blue drive is adjustable.

This is a 90's Zenith CRT. Weak guns are the norm.

Heh, know what's funny? On the sticker, it says to replace with a genuine Zenith CRT...LOL!

"Yeah! We want you to use only Zenith CRT's, because our competition's CRT's last too long! Our replacement CRT's cost more then a new TV, so either way CHA CHING! $$$!

zenith2134
04-08-2009, 10:26 PM
All Zenith color sets post-roundie era had the "replace only with a genuine Zenith tube" sticker...some said to use Rauland or Zenith replacements. Same shit. Except back then the tubes were some of the best you can get a hold of (pre-77ish) unlike these tubes which go bad almost hourly lol.

My '89 Zenith has a great picture after tweaking the hell out of the G2, kine bias and customer controls. Might hang on for another year or so, but man it does look good.

If you have a suitable replacement, give it a whirl. Just be careful, and the worst case situation is the set gets tossed. I've done 2 tube swaps and they're not too bad but can be frustrating when setting purity.

MRX37
04-08-2009, 11:13 PM
Don't have a "genuine Zenith" CRT, and I wouldn't go through the trouble anyway. Picture's good enough to sell now. I'll sell it cheap, so I can get the parts needed to repair a TV that has a better CRT.

radiotvnut
04-08-2009, 11:33 PM
I remember back in the mid '90's, the Zenith 27" CRT's were over $400 and the Opta-chrome rebuilt tubes were about $160. I actually bought one of those opta-chrome tubes to put in a higher end Zenith set. A couple years after I sold it, that tube shorted and took the power supply with it.

Dennman6
04-09-2009, 05:38 PM
[QUOTE=MRX37;2655440]The picture's still surprisingly bright enough, but it's tinted blue. Adjusting the color drive controls on the CRT neck board made things better, but it's still tinted, and the blue drive is as low as it will go...

Got a 1995 Zenith Color Sentry 27" table model that belonged to my dad. He had it set up in an entertainment center along with a Pioneer receiver & cassette deck, Sony CD player, Technics belt drive TT, JBL speakers, RCA Hi-Fi VCR. In the fall of 2005 the thing went dead, after months of intermittenly going too pink all the time. He took it to Leon's TV here in Indy where they repaired the power supply. Held really good color for about a year, then went to nearly all green screen. After dad died 2 years ago, I decided to fiddle with the screen & drive controls-found out the only adjustments were on the board at the end of the CRT! Wow, things sure changed from his previous set, a 1978 RCA ColorTrak 25".

Not really enough adjustment range in these 1990s Zeniths-I'm still not satisfied with the color balance. Yet the tube is still bright & has quite good focus. Meanwhile my sister gave me a 1996 Sanyo 25" that has an excellent, lush, "Technicolor" image to it. Never been serviced, made in USA. Zenith of course, is a Mexican set. Go figure!

MRX37
04-09-2009, 05:59 PM
Yeah, this TV also has its color adjustments on the CRT neck board. I don't know if they're drive or bias adjustments, but I've managed to acheive a decent white balance on this TV. Red still looks a bit weak, but it's good enough to sell.

radiotvnut
04-09-2009, 06:01 PM
Most, if not all, later model CRT sets do not have actual pots for adjusting the CRT bias. Instead, the CRT bias is adjusted via a service menu that is brought up by using a special code.

zenith2134
04-09-2009, 06:19 PM
The code was 9-8-7-6 enter, right?

My '89 is pre-service menu which may be a good thing...:scratch2:

sampson159
04-09-2009, 06:37 PM
i have a 27" zenith tube that i was going to throw away.this crt is like new and i really dont want to trash.if you are close to columbus,ohio-come and get it.if not,okay!

Dennman6
04-09-2009, 06:45 PM
Yeah, this TV also has its color adjustments on the CRT neck board. I don't know if they're drive or bias adjustments, but I've managed to acheive a decent white balance on this TV. Red still looks a bit weak, but it's good enough to sell.

I've read here about these 'service codes' but never have had a need to use one. Is the code Zenith2134 mentions applicable to my 1995 Color Sentry? If not, how would I determine the code? This might make a world of difference in adjusting the white balance on this set. But then I'd need to reset what I've already tweaked on the CRT neck board, right? Which came first, the chicken(service menu code) or the egg(CRT neckboard)? In order of servicing, that is.

zenith2134
04-09-2009, 07:04 PM
Unfortunately, I don't think a 1995 Color Sentry has a service code which adjusts the kinescope bias/drive. Green screen that cannot be corrected with the videoboard's pots sounds like a bad CRT...

radiotvnut
04-09-2009, 07:43 PM
If it actually has actual pots for the CRT bias adjustments on the neck board or chassis, there is nothing in the service menu that will help you. I think they went to the menu adjustable bias adjustments in '96.