1966? Zenith Color Tube TV

[Lain94]

It appears that I managed to successfully remove the short on the red gun for now. Also successfully rejuvenated all three guns to go back into good emissions range while operating at its standard 6.3 volts.

I have to say I am impressed by how well the Zenith crt handled it. Not sure how long the emissions will stay good like this but if it stays good for the time I use it later then it will have saved me a lot of extra money and work.

[old_coot88]

Our experience with rejuvving customers' CRTs was very short lived, as they went flat again within a week or two. Then the all-new Beltron came out with a "kinder, gentler" restoration process that held up a little better. But the customer had to understand and sign a No Guarantee agreement. Or as an option, they could choose a brightener which generally gave the jug several months useful life.

[Electronic M]

I don't have much experience with weak Zenith CRTs before the V types of the chromacolor era, but the chromacolor tubes tended to wake themselves up in normal operation....As in the set will run dim for 2-15min, then get bright and stay bright for as long as it's left on. Then after a couple hours to a couple months off start dim on next switch on. I've also seen chromacolor tubes that test questionable emissions wise and still look fine without a brightener (where other tubes would be dim at that emissions level)....This is part of the reason I hoard CCII CRTs.

I just factor in the inconvenience to using the set and turn it on early.

[zeno]

Good to see the results were positive. A few notes left.
The isolation brighteners I used had an isolation only option.
Newer sets used a different brightener since the CRT F ran off the FBT.
They also had isolate only option. There are other tricks on in-lines
that will even help a soft Trinitron jug look better. Its all about kicking the
can down the street & getting sets picked up.

Rejuve was useful & sometimes a money making racket.
It worked & could get another 6 mo +++ out of a set. We charged an extra fee BUT gave a "coupon" with no limits for a new set of the same size or greater.
Basically it was " make your best deal THEN hand this to us & we will refund
the rejuve fee". It worked quite well.

73 Zeno
LFOD !

[old_coot88]

Originally Posted by zeno

The isolation brighteners I used had an isolation only option.

We tried one once for H-K shorts, and it blurred out fine detail in the pic due to parasitic capacitance between the windings. This was on a color roundie.

Newer sets used a different brightener since the CRT F ran off the FBT.
They also had isolate only option. There are other tricks on in-lines
that will even help a soft Trinitron jug look better.

There's often a heater series resistor of maybe 2.7 or 3.3 ohms (located on the neck board) that you can shunt. Does same thing as a brightener.

[Lain94]

Finally mustered up the patience and time to finally pull the chassis out of the Zenith. I more thoroughly cleaned it up as well as the inside cabinet. I used deoxit on all the pots. I am going to replace all the electrolytic capacitors, paper in oil caps, wax papers, wax paper safety caps ect. I even found at least one bumble bee cap and a sprague black beauty. I ordered the replacement capacitors needed from Digi key and am waiting on those.

Also checked on the bulb near the tuner and surprised to find that it is not burnt. I also plan on testing all the diodes in circuit using a multimeter. Will check thermister, flyback, and other transformers.

Oh and I somehow managed to find and buy a NOS Thordarson Vertical Output transformer for this tv. So if that transformer is bad or does go bad I will be ready for that.

I already clipped out two wax paper caps to examine more closely and made note of their location. Also will be needing to get a replacement inductor or two for the convergence board that is screwed on the top part of the wood cabinet as the plastic is literally turning to dust and falling apart.

I am planning on doing a full restoration of this tv to look like new in performance. I will even eventually work on restoring this wood cabinet. Cataracts look minimal on the screen. Speaker fabric grill needs replaced as it is all chewed up.

Two wires got pulled off and will need to be resoldered but that is no big deal.

Taking this apart today gave me quite the workout. lol

https://imgur.com/a/jRTnZ2V

[Jeffhs]

Originally Posted by Lain94

Finally mustered up the patience and time to finally pull the chassis out of the Zenith. I more thoroughly cleaned it up as well as the inside cabinet. I used deoxit on all the pots. I am going to replace all the electrolytic capacitors, paper in oil caps, wax papers, wax paper safety caps ect. I even found at least one bumble bee cap and a sprague black beauty. I ordered the replacement capacitors needed from Digi key and am waiting on those.

Also checked on the bulb near the tuner and surprised to find that it is not burnt. I also plan on testing all the diodes in circuit using a multimeter. Will check thermister, flyback, and other transformers.

Oh and I somehow managed to find and buy a NOS Thordarson Vertical Output transformer for this tv. So if that transformer is bad or does go bad I will be ready for that.

I already clipped out two wax paper caps to examine more closely and made note of their location. Also will be needing to get a replacement inductor or two for the convergence board that is screwed on the top part of the wood cabinet as the plastic is literally turning to dust and falling apart.

I am planning on doing a full restoration of this tv to look like new in performance. I will even eventually work on restoring this wood cabinet. Cataracts look minimal on the screen. Speaker fabric grill needs replaced as it is all chewed up.

Two wires got pulled off and will need to be resoldered but that is no big deal.

Taking this apart today gave me quite the workout. lol



https://imgur.com/a/jRTnZ2V

I hope you get this Zenith TV working as well as it probably did when new. Zenith has always been my favorite brand of TV, even after the DTV transition and Zenith's move to Korea from Chicago in 2008, so when anyone here on VK talks about one I will read the post with great interest.

BTW: How did the speaker grill on yours get so chewed up? You didn't mention pets, etc. getting at the fabric and chewing on it (cats will often do this, as well as chewing on wiring; I had a cat several years ago that chewed through the insulation on my computer's printer cable and, needless to say, destroyed the cable in one fell swoop), but it can happen, as my note in parentheses stated. It is fortunate your TV's speaker cone and/or the wiring to the speaker wasn't damaged by whatever chewed on the grill.

[Lain94]

Hard to say exactly why the speaker grill was chewed up. My best guess is rodents. As there was rodent poop in the wooden cabinet of the tv where mice took residence at some point in the past.

I got this tv from someone who had worked at an e waste center, they did not have the time or interest. So while this tv is in rough shape, at least I managed to save it from the landfill.

I also noticed the HV area was just coated with tobacco tar and nicotine glaze. I know most people smoke back in the 1960s so I was not surprised to see evidence of the prior owner being a smoker but was in awe at how much gunk built up. I guess smoking probably caused a short in the HV area at some point.

So you can call this Zenith a smoker's choice set!

[Lain94]

Brief update: I also now acquired a NOS flyback transformer for the Zenith!

[Lain94]

Chassis has been thoroughly cleaned with a toothbrush to help loosen up residual dirt, all tubes have been tested with multimeter for a basic filament test already, sockets cleaned.

Diodes have all been checked out and tested and appear to be ok. Some weird looking tophat shaped diodes are on this chassis. I guess these were a thing once upon a time. Also some normal glass package germanium diodes, along with fairly normal looking diodes.

Still unsure of the exact reason this tv was no longer being used ages ago but clearly has something to do with the HV and horizontal output tube. The 6JS6 tube does look a bit used visually but I do not have the a tube tester atm to do anything more than a filament test. It is quite possible though that the 6JS6 tube may have failed in this tv. It would hardly surprise me since it is common for horizontal output tubes to fail in tvs directly on their own from use or as a consequence of something else failing.

My current guess is still tobacco smoking contributing to tar buildup in the HV area which likely caused arcing.

Next step is to use a dremel that I recently bought to saw off the can caps, leaving terminals in place and recapping. Also will have to check the transformers including the flyback with a multimeter eventually.

[Lain94]

Unfortunately three coils basically adjustable inductors had the plastic cracked due to age. L40, L41, and L42. They are all for Dynamic convergence. Any ideas on where to find replacements for these? Do they even make them anymore with these range of values?

Also found a date inside the cabinet along with some random number.

September 21, 1965

1 4 6795

Any idea what that string of numbers means?


https://imgur.com/a/yZrbeLP

[Lain94]

Update: Zenith chassis fully recapped, all waxpaper, paper oil, and electrolytics replaced and put in and checked. Flyback winding for HV rect. tube cup and horizontal output tube cup tested ok, will test remaining windings and transformers soon. Cleaned chasses more, deoxed all pots and cleaned tube sockets, all tubes tested and some are weak but none straight up bad or with unacceptable leakage or shorts. Likely the CRT just got so weak that tv was put out of service for that reason. Also the CRT having a short on the red gun was probably the straw that broke the camel's back and put it out of service too. Like mentioned before, it appears the rejuvination and fixing of short was successful, only time will tell if it holds up for long when put back in service later down the road. Diodes checked out ok.

Found all three needed replacement inductors for dynamic convergence board L 40, L41, L43. Replacements are all NOS and will be installed soon.

Accidentally cracked the burst amp inductor on underside of chassis. Ferrite core was unharmed though, one of the wires pulled of a post and is now too short to reach. Repaired the plastic crack on inductor but wire still needs to reach post...ordered a NOS replacement for this inductor in case I need it...price only $15 plus shipping lol. And like I said before even IF flyback and vertical transformers were toast...I have NOS replacements for those too ready. So I am sure this TV will have a new lease on life but the tobacco tar fumes may be a bit...off-putting for some.

Any tips for fixing an inductor whose wire is too short to solder back to post? can I just patch it in with another wire of make the metal connector post longer?

[Electronic M]

Just bridge it with another piece of wire. Try to keep guage similar, and try to avoid excessive lead length.

[zeno]

Coils
You can rewind coils onto another form. All Zenith conv
panels through the hybrids used them. Swap the slug too !
Panels have a S-##### number that may have a sub. I can look those
up.

Rejuve
Kicks the can down the street. Gives the cust time to save up
the $600 +, a LOT of $$$ back then. Using a modern B&K
or Sencore is best on clean & balance. Heavier settings are
last ditch. Results seem best when you get lots of needle swinging
& flashing in neck. Unpredictable but can stretch things a few
years at times.

Zeno

[Lain94]

Originally Posted by Electronic M

Just bridge it with another piece of wire. Try to keep guage similar, and try to avoid excessive lead length.

Thank you! That was what I was thinking I could get by with doing but just wanting to verify before I made another goof up. I luckily so happen to have some wire of that gauge roughly, it is known as "wire wrapping wire" which also tended to be the gauge for some fuse wire I needed when replacing the wire fuse on my old motorola tv way back. I will compare and see how close the gauge is or if needed I will simply get some more fine wire. I did manage to order a replacement NOS inductor specifically meant to replace this one on the zenith luckily...price $15 plus shipping lol. I keep lucking out with this tv when it comes to replacement parts really.

First I manage to somehow get a NOS thordarson flyback for this tv...then a vertical output transformer NOS thordarson brand....then I got all 3 inductors that I needed which had broken due to old plastic cracking on the dynamic convergence board...and now this inductor lol. This tv is getting five star treatment by me. XD