Hey y'all, where could I find a schematic for this set? It has the "Super H20 Chassis" in it. I dont know at the moment if there's a more specific chassis identification code or not, just let me know if there is and I'll see about pulling the tv out of the corner to have a look.
General gist is that the set seems to be developing issues, and I'd like to turn it into a daily driver. I also got to get it apart sometime to give the flyback some attention. Last time I took a peak at it, it looked like all the black coating fell off and was laying in a pile of chipped off pieces. (Mabey the reason it sounds like a burning cigarette with the back off)
I've got more I could add but I'm out of time

"where could I find a schematic for this set?"

In Sams Photofact 467-2.

.

That's the 16D21 chassis, also in the Zenith manual TV-23. If you can't find a copy, I can scan the schematic either out of the sams or the zenith manual.

Hey y'all, where could I find a schematic for this set? It has the "Super H20 Chassis" in it. I dont know at the moment if there's a more specific chassis identification code or not, just let me know if there is and I'll see about pulling the tv out of the corner to have a look.
General gist is that the set seems to be developing issues, and I'd like to turn it into a daily driver. I also got to get it apart sometime to give the flyback some attention. Last time I took a peak at it, it looked like all the black coating fell off and was laying in a pile of chipped off pieces. (Mabey the reason it sounds like a burning cigarette with the back off)
I've got more I could add but I'm out of time

Sounds to me as if the CRT is shot. The black coating flaking off the bell of the tube (the aquadag) acts as a huge capacitor in the high voltage system. Without it, the CRT cannot get 2nd anode voltage, which will of course kill the raster.

I'm not sure where the sound you're hearing is coming from, but it seems to me that the missing aquadag on the bell of the CRT may have a lot to do with it. In any event, the tube is now little more than a glass jug and must be replaced. :no:

Lost dag on the exterior of the CRT can easily be washed off and re-applied... The CRT may be ok... more testing is needed before counting the CRT as "shot".
The dag is used as a filter capacitor for the HV supply, but its absence will usually just cause more AC "ripple" on the HV... HV is likely still present, and likely arcing, perhaps to the flakey dag or from the flakey dag to the chassis ground strap.
But it really sounds as if the flyback not the CRT is the source of the black flakes?

jr

I also have a h20 zenith space command. I'll look and see if I have the schemstic for it.

Thanks for the info guy's.
Adam, thanks for the offer. I'll have to take you up on it if I dont find anything. I'd like to see one soon, to at least find out what the electrolytics in this set are, to make an order if I have to.
My picture tube is fine. (look at my avatar pic) It hasn't been tested, but it gives a great picture, and is way too bright if I crank the brightness up. Nothing is or has been flaking off of it. If it was, the chassis would be dirty with it.
No, all that crap that I was talking about is in the high voltage cage. There still is a little bit on the hv trans, but most is off. It's also hard to get into the hv cage on this chassis, so i've never gotten a good look at it.
Hey Radiotronman-Nice set! Looks exactly like mine other than the case. Does it have dual speakers?

40uF-400V
80uF-400V
100uF-50V
10uF-400V
4uF-350V
20uF-25V

^Oh, wow... you got that right off hand?:zoom:
Cool, I'll have to check my stash now, and make an order.:yes:

Well, I found some pics of this set, back when I had it in storage and right after I got it in the house. The Chassis number is 16D21Q. Also have a question for those who have taken one of these apart. Does the CRT stay in the cabinet or is it bolted to the chassis?

Here's a few pic's!:banana:

I HAD a set one year newer than this one (16E21Q.).(cabinet got RUINED ...by water ...in the old garage..) Still have chassis and I think tuner SURE I have SC chassis. it DID somewhat work...last time lit off. Tube DID come off with chassis IIRC.

That SUCKS^^^ Mine's got damage on one side as well. Not water though, I think it saw the sun for years. Good to know about the CRT. I don't have to disconnect anything from it.

Mine was MUCH worse. I would NOT have scrapped it if it had looke dlike yours. but instead...the back cover had DISINTEGRATED...one whole SIDE was rotted away and the bottom was crumbling...

Tube on mne was GREAT in 98 or so last time i had it lit.

Almost sure nothing needed to be unhooked to remove chassis/tube assy frm mine.

^WOW, how high had water gotten?! Sounds like the chassis would've been wet aswell. That's pretty impressive for it to still work as well, if it got wet.:yes:

It's great to know that I don't have to pull anything apart right away. Hopefully I can get the whole thing in the basement to my bench all together. I'm sure glad I don't have to take it up and down the stairs several times to check my progress when I recap and make a few modification's. I plan on keeping the case up on the 2nd floor. It was a pain getting up their. Would have been better if we used a dolly....:grumpy:

I have this set as a tabletop version. Before it was given to me, it had a metal base that swivled under it. Mine is untouched since 1974, and has the oem remote.

I had the 24" 18C24Q Space Command console for a long time. Beautiful set, but hard as I tried in the classifieds, nobody would take it. I saved the chassis, tuner, and remote sub chassis if anyone has needs. Just let me know. Parts like new as was the set for the most part........ :(

That sucks^^^

It'd be nice if mine was a 24"....

Anyway's I ran the set for an hour tonight, watched All in the Family on antenna. Took note's on operation of the set and things I want to improve apon/eliminate.
Got a few issues i'll write about in another post. Also plan to modify it a bit. I saw on Phil's site, an article about adding AV jack's(RCAjacks). They give the best image, sound, and make it easier to hook up some video game systems.:banana: Also want a shut off switch for the tuner when using an AV jack, to conserve some power.(if possible)

If you can find a video injection point where the circuit wants the same amplitude and polarity of video that the Composite standard provides let us know (a lot of Zeniths with that chassis design survive today)! You may need to add a low-pass filter to remove the chroma signal to prevent dot crawl or get the signal from the monochrome pin of an S-video jack or the green jack of a component video trio.

That sucks^^^

It'd be nice if mine was a 24"....

It really did! Those are supposed to be great chassis for everyday use if desired. I recapped the entire set, checked all resistors; the whole 9 and the set never improved a bit from the way it was found.

It was found in near mint condition with very little vertical sweep, no sound or video, and only a volume adjustable hum coming from the speaker. Not one bit of improvement after all the work done made me put it to the side for a long time. I yanked the chassis one final time and did find an open coil in the video detector circuit, but that's all. As well that go round I disconnected the wires to the vertical output transformer and checked the windings. Never found a problem there.

The CRT didn't come out with the chassis, so I never did a proper voltage check. I needed one of those test CRTs, but it just wasn't meant to be I guess. New woman in the house cost me a few electronic gadgets and that was one of them. Again, if you ever need parts I have them......:thumbsdn:

^^Huh, something was off.... Sound's like something could've been screwy in the power supply but, IDK. I would of been stumpt as well.:headscrat Ok (about the part's) Honestly I doubt I'll need any though, unless my flyback is actually f'd up and keel's over:worried:


If you can find a video injection point where the circuit wants the same amplitude and polarity of video that the Composite standard provides let us know (a lot of Zeniths with that chassis design survive today)! You may need to add a low-pass filter to remove the chroma signal to prevent dot crawl or get the signal from the monochrome pin of an S-video jack or the green jack of a component video trio.

Thanks for the idea. I've still got some figuring to do, but first I need the schematic!:scratch2:

Schematic-Anybody??:para: Anyone got a schematic scanned for a 16D21Q...

Schematic-Anybody??:para: Anyone got a schematic scanned for a 16D21Q...
Hello Zack,
I scanned it for you and submitted to the ETF. Send me your email if you would like me to fwd it to you.

^Hey, Cool, thanks alot, I sent ya a PM.^

This may be a stupid question to some of you but... Can I tip this chassis over on it's side with the crt still on it, or is it greatly recommended that I take the CRT off? I don't want to take it off. But this is the largest i've ever dealt with so far, and I don't want to stress the tube much by putting on it's side, if it's an issue.

I've worked on them on their side before. The two things to watch out for are loose CRT mountings (if it can move relative to the chassis in any way the neck could snap), and the 5U4 melting a hole in the rug I was working on top of. If that VCR your parting out still puts out good composite video (either from the tuner, mech, or passed through the inputs) then use it as the video source...If you accidentally fry your test video source it is better if it was a junker unit.