Is this Zenith worth the effort?
 

Hey all, i found this on C-list and i am pondering if it is worth it. the model is a L2320PN2 in a wooden floor cabinet from 1979.
here is a link to the ad. https://nashville.craigslist.org/atq/6076842733.html
the pics on c-list show it working with snow on the pic tube. " i don't think they have anything with a rf output to test it. i've been quoted a price of $75. Great buy? Problem set? etc ?
thanks Logan

CRT looks strong in pic 2.

CCII vertical chassis deltagun set. Probably the last of them if they read that date off of the back. It is an SS set. Aside from dirty tuners and needing to clean module contacts/reflow solder when they get intermittents they are fairly bulletproof sets, and perform well. I have 2 similar sets one is a 1976 and the other is a 1978...Got both for free.

I think $75 is on the high side unless you want to value it for the CRT (in which case that would be cheap).

I'm thinking of scrapping my '78 for the CRT and the space...

Cant tell 100% but probably a gen -2 system 3 type chassis.
To be labeled System 3 must have RAT tuning, color
sentry, EFL CRT & comb filter. S-3 is a feature list
NOT a chassis name for the style.
Anyhows what ever it is its a good looking set. CRT seems
VERY strong & almost any problem is easy to deal with.

73 Zeno:smoke:
LFOD !

Nice looking set, personally, unless you've been hunting for this specific model, $75 seems a little high to me, here in Kansas anyway, Zenith's from that era can be had pretty cheaply.

It's a CC2 (you can tell from the tube cap on the back) If you like it, get it. Best picture of any solid-state set of that era. Tom nailed it on common issues. It's either gonna work fine as is, or you may have to reseat the modules. You're gonna have the "re-cap spazzes" chiming in soon. 1) It won't have the "bad" safety cap 2) It's new enough that you will NOT have to recap anything.

You are right most CCIIs that don't need safety caps often have all the caps good, however a small percentage of sets will have a bad resonance cap in the VRT transformer supply, or occasionally a gray tubular lytic fail*...Both cases are rare enough that preventative maintenance is entirely unmerited.

*My flat chassis Avanti had that (100uF 50V under a chroma module) and it caused the screen to be horizontally half in color-half in monochrome.

Hi All, the person emailed me and said he would take $50 for it, well i couldn't resist, Even though they are common elsewhere. i haven't a 70's zenith in almost a year. I brought it home and after a little adjusting.......

Awesome deal, and a fine looking set!

Looks like a really great picture on it. How is the sound?

volume is a little scratchy, but when you find a good spot on the control, it is clear.

Looks nice!

My Electrohome has a similar problem: the color fades toward the right and then drops off sharply on the last third or so. It's especially visible with the DVD player on but with no disc loaded. A cap kit is on its way.
A little DeOxit or MG Chemicals Electrosolve (my personal choice) and it should be as good as new.

Hey All!, now that i've had this set for a while i have noticed a little problem. after about 15 mins or so, the tuner drifts ever so slightly off of channel. first thing i notice is the image goes to B&w instead of color. I've reseated the chroma board, so i think it is a tuner prob. if i switch channels then back to ch 3 "which is what my converter output is" the color comes back no problem and will look good for 20 mins or longer. The chassis is a 23lc45z1 if that helps. any ideas?

I was worried about that, and was watching this thread to see if a tuner issue cropped up. Those electronic tuners could be a pain in the ass, and were showing problems by the late 80's. It's Electronic, so there is no cleaning.
Start with the obvious... turn the AFC off, tune it in to the strongest signal/pix/ turn the AFC back ON. If it still has the problem, the tuner is a module, and you'll need to replace. If that's the case, let us know which one. It's listed on the schematic.

The AFC switches get noisy. So do the pots in the selector.
IIRC it has 2 tuners & a tuner control board. Check the board
for cold joints especially under the connectors. Some tuners
had connectors on them, same deal.
After that its an AFC problem which I doubt........

73 Zeno:smoke:
LFOD !

Ok this is what happened after i did that, I tuned in the pic with the afc off on ch 3, when i would turn on the afc switch , it would detune to a unviewable picture. When i tune in the tuner while the afc is on i get a regular pic for 10/20 mins or so.
as far as the tuner module number i could only find 2 numbers in reference to the tuner, first is 175-5074-01 plant 12 on a sticker on the tuner and 3439626 stamped in red ink on the tuner itself. The diagram on the inside of the cabinet only list the modules on the vertical chassis. I know it says on the module to not use contact cleaner on the tuner but what is the failure mode on these tuners, corosion? can they be repaired? I used to collect and repair watches as a hobby, i think i could dismantle the tuner if i knew what to look for.

What happens if you just leave AFC off? If you're feeding it through a modulator on channel 3, AFC shouldn't be necessary anyway.

By the book
Turn AFC off
Tune all channels for color pix without "worms"
Turn AFC back on. Should be good for years now.
Even with AFC off the set should work for years OK.

Selector module has only the following IIRC
AFC switch
Channel switch
18 tuning pots
AFC defeat switch ( defeats AFC during channel change )

Trouble shooting:
We did change some for erratic ops IIRC.
Try tuning ch3 on another slot (2 or 4)
Try tapping selector, VHF tuner, TNR control board &
150-190-01 IF module.
Defeat AFC by grounding the blue/white wire at tuner.
Monitor the tuning voltage at tuner. Dont remember color but its
NOT red, yellow or blue/white.
CHECK FOR COLD JOINTS !

CU later Zeno:smoke:
LFOD !

well last night after trying the text book method that failed on channel 3, i switched the converter output and tv set to ch 4 and tuned in the set, it would detune a couple more times that evening, I fell asleep in my chair watching Svengoolie but as i awoke the next morning the set was still showing a great picture after being on all night. I think i will keep my eyes open for a 175-5074 tuner control "module and the tuner module "is this on the backside of the chassis or is it the long metal box or the left side of the chassis?" and have spares ready if i want to clean/repair these parts. Thanks everyone for their help and suggestions.

It's the one that the tuning knob attaches to.
It's been years since I changed one, but it's basically "plug n play",
If it works on CH 4, and stays that way, I wouldn't worry, but if you come across a module I would snag for a spare. The tuner is totally electronic, so there is nothing to corrode. I can't remember what the specific part failed on them, but it was common. Doug Harland would be the one to explain how that works.

Hey everyone!, Sorry for resurrecting a long dead post but i have a new development: over the Holiday week i had a chance to install a new part. On ePay i found a new tuner control... module... selector whatever it is called. My set uses a 175-5074 module and i found a 175-5073 for cheap. The difference is the connectors and the angle of the base plate, It is used to connect it to the cabinet and tuner module which is a 175-2026 module. Well long story short, i found that the mechanical parts "variable resistor boards" are the same. this unit uses printed circuits on a ceramic substrate and are connected via a socket(s)????. I dismantled both units and swapped the new substrates for old and now the set has rock stable channels and has no de-tuning after a few days. Just thought i'd update my latest work with it's outcome. Logan

Well done !
For future reference there are 2 major varactor tuner set-ups
in Zenith CC2 sets.
Early sets used separate UHF & VHF tuners ( 175- ### ) a tuner
control board ( 9-###) & a selector assy ( S-##### ).

Later sets used a big combo U/V tuner ( 175-#### ) & the
selector assy.

If you have more drift resolder the connectors on the big tuner
or if it has a control board on that. If that dont do it pull the tuner & look
for cold joints especially at the shield points.
BTW Selectors were known to drift but I dont know why. We just
swapped out the unit, it was faster & cheaper than troubleshooting
it.

73 Zeno:smoke:
LFOD !

I was servicing those sets when they were relatively new. The 175-5074 and 175-5082 "tuner packages" were troublesome, and eventually Zenith started selling just the selector switch assembly as a replacement part.

I don't suppose you might remember the zenith part number for the selector switch assembly? I'd like to find a few spares on ePay just in case.

Also, those models had a neon lamp probably a NE-2 bulb illuminating the channel display. Set looks nice.

Sorry, but I can't remember the part number; I do think that it started with the letter A, and they called it a "substrate".

I've always been curious, did these last model 23v CRTs have the delta gun/dot phosphor CRT or were they inline? I've never seen one up close, but cant imagine why they would tool up for an inline 23v style crt with readily available onlive 25v styles.

Zenith made CCII deltagun 23 and 25" into 1978... inline became an option on CCIIs in 76 IIRC. I believe the system 3 was all inline.

CC2 chassis used delta gun black matrix CRT's 17", 19", 23", 25".

The 13" introed in 1975 ( G line 1976) used a conventional in line CRT

In H line 17" & 19" in line EFL CRT's were used on the better models.
A hand full of them could light up Fenway Park they were so bright...

K line sets marked "System 3" used the EFL in 19" & 25"

L line had the last CC2 delta, a 23" set. All others were EFL

M line was ALL EFL's 13, 19, 23, & 25 inch.

73 Zeno:smoke:
LFOD !

For $50 and a little adjusting, you did fine. And one of the best ever USA TV sets at their best. Kent T approved!!! :tresbon:

Thank you, after 2 years and another tuner module for parts on ePay, I regret nothing! I just wish more of these "last gasp" delta gun sets would show up around here!

Looks good!

I'm interested to see how the first 13 inch inline CRT looked in 1975. I know my 1978 chromacolor ii is insanely bright.

That 23v deltagun CRT must have been the last bastion of those ever made, meaning black matrix and all the advancements in that period put into the CRT. By this time, inline CRTs were well under way, and around this time, Sony was ready to roll out their 25 inch Trinitron, which I believe wasn't til 1981 if im not mistaken, so the inlines were being kicked out in full fashion. I find it fascinating, that Zenith designed this chassis with all the latest advancements, to push the last remaining 23v style CRTs out. Especially in 1979, when everything went to the 25v style years back.