After fixing the last Zenith I found only to discover its CRT is shot, I want to know if I should try fixing this one. It was manufactured in November of 1989, so I HOPE it's before the era of bad Zenith CRT's.

This TV won't power up. No click, no sound, nothing. It acts as though its not plugged in, even though the cord is fine and the outlet has power. I know the cord is fine, as this TV didn't have a cord and I used the one from the last Zenith I had. (perfect fit).

So, should I try fixing this one? It has AV inputs, so that's some motivation.

Does it have a switching power supply board bolted to the right hand side (looking from the back) of the cabinet? If so, look for bad caps. I think I remember a 47 uf electrolytic going bad and causing a dead set.

Also, if that set uses one of those "membrane" keypads, that could very well be the problem. Try turning it on with a universal remote.

'89 was before the CRT's got really bad. I have, however, seen plenty of weak ones from the late '80's. I would say that you'll have a better chance with this one than with the newer ones.

No switching PS bolted to the side of the TV that I can see.

The TV has hard plastic buttons. I assume that means no membrane keypad.

My 27" 1990-built Zenith has been in near-daily use for 18 years, and the picture is still excellent. However, an identical appearing 27" set purchased for my grandparents in '93 was junk within three years. :thumbsdn:

OK, is it the "flat on bottom" chassis with the power supply/deflection board on the right and the main module on the left? I think there's a 100 uf cap close to the main filter cap that will fail on the "dual module monster" that will cause it to be dead.

It might be better if you could give the module numbers. They are usually more familiar to me than the set model number.

Main module is 9-871

Sweep/Power supply module is 9-874

So, where should I start looking on this one? I'm going to try and save it. If it was even 2 years newer I wouldn't bother, but maybe, just maybe the CRT is good.

The problem will probably be on the 9-874. See if there's a 100uf, 50V cap close to the large electrolytic filter. They usually measure very low on a capacitor tester. I think I may have a good power supply module for one of those sets. I'll see if I can find it tomorrow and check the number.

Okay, found and changed a light blue 100uf at 160 volt cap. The TV now turns on, but there is no picture. I hear a faint crackling from the speakers. No on screen menus either.

Another update: I connected an antenna and turned the Tv on, and got a picture! The static looked pretty bright. I tuned it to a channel and was rewarded with what appeared to be a decent picrure. i didn't scrutinize it too closely, as I turned the Tv off to reconnect the speakers. TV turned off, now it won't come back on.

I'm going to resolder any suspect connections in the power supply, and maybe replace any relays I find.

I've seen bad connections on those power supply boards. Also, make sure all the plugs are firmly seated.

I have not uncovered that power supply board yet. I've still got some more digging to do.

I *think* I've fixed the power supply board. The TV is up and limping now, and I'm presented with a new issue:

http://i119.photobucket.com/albums/o121/mrx3750/Zenith2.jpg

This is Channel 62, the strongest station in my area. I have a pair of rabbit ears connected to this TV. This picture should be crystal clear, but it's not.

Someone before me was inside this TV and messed around with some of the coils. After some diddling around with them, I got a picture like what you see in the above photo. I can't get the picture any better then this. Luckily however, the image is stable and smacking the TV doesn't affect it, so I think I can rule out a bad connection. Other then that, I am at a loss on what to do now.

PS: The CRT seems to be in good shape for being almost 20 years old.

If someone has been screwing around with the coils; you may never get it back right without an alignment generator. How does it look through the video inputs?

That CRT does look very good to be a 20 year old Zenith tube!

How does it look through the video inputs?



Good question. Can't find a button to switch it to video. Can't find an option for it in the menu either :-/

I'll diddle with it somemore tomorrow.

On those Zeniths there should be an input menu. If it's not there, someone might have gotten into the service menu and told it there is no video input.

This is from an old newsgroup post (I'm not sure if it's correct, but it's close):

To access the service menue from the front panel
press and hold the"menue"key until the menue disappears.Then without
delay press simultaneously the "adjust Right"and "Channel up">Use
"select Up/Down"key to toggle through the menue to go where you want to
go to.Press "Enter"to exit the service menue.(You may have to
press"Enter"twice on some models).

Can't find a button to switch it to video. Can't find an option for it in the menu either :-/

I'll diddle with it some more tomorrow.
Some TV sets use "channels" like 0 or 1 or some in the 90's to switch to their video input(s). Try a bunch in those ranges.

Chris is right. The RCA CTC121-130 chassis sets used 91/92/93 for A1/A2/A3 (aka the rca composite inputs) threw me off for a while.

Chris is right. The RCA CTC121-130 chassis sets used 91/92/93 for A1/A2/A3 (aka the rca composite inputs) threw me off for a while.

Uhh... huh... Yes but this is a rebadged Zenith... not an RCA...

In any case, having owned an RCA Colortrak, one of the first things I tried were the channels.

I didn't spend a lot of time trying to get the TV into video. Tomorrow I'll make that my top priority.

Some of those Zenith sets had an option in the service menu to turn off the A/V jacks. The problem is: I can't remember how to get into the service menu on these older sets. I think the video input channel should be between the highest and lowest RF channel that is programmed into the set. There may be something in the customer menu to set the video inputs to whatever channel you wish.

Some Zenith's used channel 0 as the A/V input, but I don't think this is one of them.

On those Zeniths there should be an input menu. If it's not there, someone might have gotten into the service menu and told it there is no video input.

This is from an old newsgroup post (I'm not sure if it's correct, but it's close):

To access the service menue from the front panel
press and hold the"menue"key until the menue disappears.Then without
delay press simultaneously the "adjust Right"and "Channel up">Use
"select Up/Down"key to toggle through the menue to go where you want to
go to.Press "Enter"to exit the service menue.(You may have to
press"Enter"twice on some models).

This does not work.

I still haven't figured out how to switch it to video.

It's been a long time, and you can probably find some other methods of entering service mode if you google. It's something along the lines of what I posted. I'm pretty sure your set is too old for the more common "menu 9876 enter" to work.

Okay this TV's taken a turn for the weird!

I prorammed one of my universal remotes to work wioth it... and EVERY BUTTON on the remote brings up what I believe is the service menu. (Adjustments for horizonmtal position, etc) However, no option to turn on the video jacks.

I opened the IF can to see if there was another coil I could adjust. There aren't any. The only adjustable coiuls have already been diddled with, and those only can get the picture to what I showed you guys in the last photo.

There is a Channel 0 in Cable mode, but it's not a video channel, and doesn't show up when I set the TV to broadcast mode. There are no switches on the back to change it to video mode, and my universal remote won't do anything except bring up the service menu!

This TV is harder to figure out then a 15x15 Rubiks cube.

Okay I have an update!

I managed to enable the AV jacks! I had to go into the service menu and set the 'Enviroment" variable to "S4" I now have an AV jacks option in the menu.

The picture from composite video is also fuzzy!

I would say that you have more bad caps then. Check all the boards over very carefully for signs of leaking caps. The last time I worked on one of these was at least 5 or 6 years ago, and the caps were a problem then. It is worth the effort. This chassis was one of Zenith's best from the 80's, and their last good one.

One neat thing is that the A/V half of the chassis is interchangeable with other A/V boards from this chassis line. That means you can replace a mono board in a low end 19" set with one from a high end 27" that has S-video, picture in picture, and other features never found on a 19". I used to have a 20" that I did this to so I could have S-video.

As far as the remote goes, either your universal has a problem, or the TV is set to respond to different remote codes than a Zenith branded set. Look for something in the service menu like "zenith / PL". Change it to Zenith if you want it to respond to a Zenith remote.

More bad caps? Okay. I'm gonna guess they're on the video module. (At least it's not the tuner)

I think I'm starting to piece together the recent history of this TV:

Cap starts to go bad causing fuzzy picrture. Some less knowledgeable person thinks the tuner is out of alignment and diddles with the coils. That failing, they figure out how to access the service menu and fuck around with the settings in that.

My universal remote's little issue is a bit of a godsend, as it allows for instant service menu access! (and I still have no idea how to it on the front panel)

Making progress!

Found and changed out a bad 10uf cap, near where the wires from the CRT neck board connect to the video module board.

Channel 62 now looks like this:
http://i119.photobucket.com/albums/o121/mrx3750/Zenith5.jpg

And here's a shot of it in composite video mode:
http://i119.photobucket.com/albums/o121/mrx3750/Zenith6.jpg

Faint wavy lines are still visible in the picture, so I assume there is at least one more bad cap somewhere on the video module board.

Edit: TV IS FIXED!

Well, the picture is fixed anyway. Found another bad 10uf @16 volt cap near a small transistor. Changed it, and composite video looks great now! All I need to do is align the tuner a bit better (OTA broadcasting is not the best way to try and align a tuner. I'll try hooking it to Cable tomorrow.)

Thank you all for your help. If not for you, I'd have junked this TV. Now I can sell it!

Regarding the remote-control issue, aren't there some Zenith-built but not -branded sets that have a service menu option to change the IR remote codes to either "real" Zenith codes or an OEM code set? Did you look for that option?

Yes I did. No such option.

Hey, MRX, I was just making conversation about the RCA. Obviously it wouldn't help with a Zenith set!

Nice to see you got it working, though. :thmbsp:

Hey, MRX, I was just making conversation about the RCA. Obviously it wouldn't help with a Zenith set!

Nice to see you got it working, though. :thmbsp:

Ah, I was kinda tired when I read that.

And thanks!

Ah, I was kinda tired when I read that.

And thanks!

Word of advice: Never work on a TV when you're tired or PO'ed. You might just make it worse and pull one of my stunts and throw it across the back yard. I did that last night to a modern 13" Wal-Mart special. I have a very short fuse when it comes to working on junk that is responsible for the death of the TV repair industry.

Word of advice: Never work on a TV when you're tired or PO'ed. You might just make it worse and pull one of my stunts and throw it across the back yard. I did that last night to a modern 13" Wal-Mart special. I have a very short fuse when it comes to working on junk that is responsible for the death of the TV repair industry.

Ohh ho ho ho don't worry. I know when I'm too tired or Po'ed to safely work on a TV. Never been shocked yet by a TV, and I don't intend to get shocked.