Fixing Zenith CCII Avante 25JC49
 

Hello! As a bit of an intro, I'm Ian in NE Ohio- local to the Zenith console tv that had been on eBay for several months. (eventually picking it up) https://www.ebay.com/itm/204588597529

I've never serviced a CRT before, but have restored a handful of tube radios and amps. Not quite the same high voltages, but I'm well acquainted with things that want to bite. I had decided that I'd like to find a Chromacolor II given their longevity, it might be the last CRT I'd ever need. (Truth be told, I built a Pixelmusic 3000 and also wanted a TV that looked the part, something neat to look at while playing music) https://ctrl-alt-rees.com/2020-11-26...-parallax.html

I never found anything local to me after 5 months of daily checking classifieds, but had been eyeballing this Avante console on ebay, wondering if I'd be happy with a console and be able to figure it out if I made a lowball offer that was accepted. Seller was asking a crazy (to me) $299 for a non-working TV that was missing the remote and (this kills my soul) they sold the base separately to someone who messaged them, so I made a lowball $20 offer explaining why this was such a hard sell, took their $50 counter offer.

The description made mention of the TV flipping the breaker, so when I brought it home, I blew out all the dust and powered the TV up with 60v on my variac. Fortunately, this allowed the TV to stay running, and sure enough, the tripler was arcing to the chassis. Of course there doesn't seem to be any of this tripler available on the internet. For the time being, I dismounted the tripler, found the crack in it, filled it with epoxy, let that cure, slathered that in a coat of RTV silicone, let it cure, and brought the TV up to full power. No more lightning! Between waiting for things to cure, I went ahead and cleaned out all the front panel control pots with contact cleaner and followed with Deoxit F5. I also saw enough threads that said to do it as a matter of course, so I resoldered the long ceramic IC on the 9-89 video output module. (Side notes- the safety capacitor that is always mentioned with CCII tvs was already the replacement orange one, and yes, I shorted the CRT per all the guides out there before getting my hands in there)

To this ignorant mind, the TV seemed to be working pretty good, just vertical size, convergence, probably other things being pretty off. I ordered a set of Philmore trimmer tools off Amazon, they came, seem to be trash & sending back, 3D printed a tool in PETG that seems to fit & work fine.

That brings me to tonight- I was using said 3D printed tool to make some adjustments per the Sams manual (nabbed that free from Cleveland library) using 240p Suite on a Sega Genesis : P

HOWEVER, this being the reason I decided to finally get on here, and get a 'build thread' of sorts started- I've become aware of something in the high voltage area softly making a sizzling bacon sort of noise while running. I couldn't see any arc or corona activity, variac is reporting a constant 1amp draw @120v (I have a cool 50's one with gauges lol) I also can't detect any ozone odor. Any thoughts on this? Thanks for the time!

Discharge the high voltage again and clean the red high voltage lead, the cup that attaches to the CRT, and the glass area surrounding the cup with a clean rag and alcohol. Let dry quite a while. It may also be that the cracked tripler has moisture in it. It will either bake itself dry, or fail again. Time will tell.

One nice thing about most tripplers sets that have a focus tap is they usually obtained focus via a high resistance divider off the HV output and because of that would self discharge the HV better than shorting does... Still doesn't hurt to double check it's discharged after all the times HV has bit me I can confirm it's not dangerous, but is definitely unpleasant.

Post the OEM tripler part # I will check for subs
Format is 212-###-##
Patching old one is not good, only for a test.
Check the CRT focus pin for the arc also. Several fixes. Cross that bridge
if you come to it.

73 Zeno:smoke:
LFOD !

That makes sense, it's probably been cracked open for 40 years. I'll give things a clean.

damen: Maybe that's why I didn't get any audible click when shorting the anode. That was unsettling in that I found myself double checking alligator clips, coming in from different angles, etc : P

zeno: the part number is 212-149 From prior threads, I got the impression that this is an oddball one but it would be nice if there are subs. Duly noted about using the patched one. I'll keep that to a minimum.

Thanks for the replies!

https://picclick.com/Zenith-977-45-T...214479930.html

note sub number. I have no idea who they are !
BTW not in 1978 Zenith parts list. Thats about when they switched
from the common 212-141-## AKA 977-36.

zeno

So far, from past sales, it seems like the box these came in had both numbers printed on it, but the same 212-149 marked part inside. The one in the attached pic sold on eBay in March, so it seems they appear from time to time. Keeping an eye out. Thanks!


I also wanted to add that I found an old thread here where it was said that this cross references to an ECG561. https://www.videokarma.org/showthread.php?t=262454
There is a used one on eBay, but I'm a bit wary that the pins being labeled differently, namely 2 of them labeled FOC instead of one being REF. Could anyone confirm that this correct?

Be careful of that one. It may be for an EFL CRT, that would have 2 focus
terminals. EFL is "extended field lens" or "tri focus CRT" big difference
is it has 3 focus grids. VERY bright & sharp. Came out in H chassii on
high end 17 & 19" sets. 13" & 25 " were added in the L chassis.

Zeno

Thanks for the heads up! I had found the schematic for the ECG model and was going to roll the dice on that one, at least to check it to see if the resistances matched up, but it didn't seem like the seller wanted to negotiate on price. (untested used, $50, not quite the right part was too many strikes IMO)

With the back of the CRT, anode cap, the lead, and the contacts in between cleaned up, things were looking and sounding pretty good today. Quiet, but then the sizzle suddenly came back, slightly at first, accompanied by white lines, and as I was reaching to power the set off, all hell seemed to break loose- almost sounded like blow torch (or an electrolytic capacitor flaming out), the screen went gray. This was in a split second before I had the set powered off and disconnected. Around back, something faintly smelled burned near the HV area.

Annoyingly, I dismounted the tripler again, assuming my patch up job let go, but I can't see anything out of the ordinary anywhere over there. I'll try to source parts before trying anything again. Perhaps also a power supply recap is in order as I understand this is the first time this has been run since at least the early 80's, and I haven't really gone about trying to 'reform' them gracefully/gradually.

Interesting... how old are the first 3 grid focus (2 adjustments) CRT? I see that are used for monitors, also (in person I've seen only last era TV's and monitors using it***).

EDIT, NOTE: ***(since I worked only in the early 2000's with TVs)

Big filer cap was reliable, IIRC I changed a few for white humbars, 24 V
supply. The big oil cap has been trouble of late. If opens pix will pulsate if shorts tosses breaker. Also can run hot first. Quick test is undo one
end & see if pix comes back.
When the tripler goes sometime the focus goes high for a time.
Causes CRT socket to arc. Will hiss, smell, & get discolored at
the focus pin.

Zeno

Good to know. The big multisection caps seem to be usually met with doubts in the context of 30's radios. A part of me has always been a little anxious of those blowing apart and spraying the surroundings with scalding hot tar : P

Near as I can tell, things are ok at the socket (pic attached) I'll follow up when I get some downtime to dig deeper, I'd think something that hissed that loud would leave a mark!

Depends on where it bites

With luck, sometimes this "deposit" can be only superficial; but, this seems to be these esay to open sockets (good to check it's innards).

Starts for now with a simple external cleaning

Bit of an update- I opened up the socket, not seeing any signs of arcing on the focus pin. https://photos.app.goo.gl/62gdRuM3AhLgeQzE6 (dumping photos off on google to maintain detail) I wish I had a before pic, it seems like possibly the connection between the focus wire and the tripler warmed up enough to melt the solder, else it was poorly done initially.

I also included pics of some possibly sketchy looking crystal formations on the bottom of one of the transformers in the flyback circuit. Are these typically a reliable part?

I've been checking around online for a good tripler for a couple months now, nothing available yet. Certainly a counterpoint to the longevity of the rest of the set haha Any tips on where to check these days? Thanks!

If you havnt try a WTB on the AR site also. So many of these sets were
built so there has to be an ECG sub. Used is possable also but I
wouldnt touch one thats cracked, bulging or discolored !

That white crap I have seen before. Seems to be harmless but wouldnt hurt to gently knock it off.

FBT's were 99.9 % reliable. If you look at the 4 tube hybrid, flat SS chassis,
& the CC2 I did 2 on hybrids ( BIG kits), none on flats & maybe one
on CC2's. Dont get better than that !

73 Zeno:smoke:
LFOD !

I've got a trippler off a upright chassis CCII I recently scrapped (was missing cabinet and chassis modules before I bought it) no clue if it's good or bad but I'm not attached to it.

chassis ## also inked on steel chassis. Need one from JC45 or newer
IIRC. must be from delta jug NOT an EFL. EFL triplers are distinctive,
they have plugs on them.

Zeno

The only time I've ever seen a FBT fail on any pre-System 3 solid-state Zenith color is when the tripler shorted and took the FBT and HOT with it (likely caused by the customer constantly resetting the breaker in rapid succession). I don't recall seeing a bad FBT on the first-generation System 3 (9-153 module), but I've seen plenty of arcing/bad FBTs on the 9-160 modules.

As far as the tripler in the OP's set, I think that's the one with 5 terminals, and I seem to remember that the ECG sub would not work (it would trip the breaker), and an OEM part may be in order here.

I didn't really care for those CC2 sets with the EFL tube. The triplers in those would short the HV to the focus lead and burn up the CRT socket, and in some cases, ruin the tube.

19EC45 it's a delta....I only have 3 inline sets (2 portacolors and a HD-CRT Sony) and won't take any more (even if free) unless I happen on a really nice spacephone set to go with my Zenith red rotary spacephone demonstrator phone.

Very informative, thank you. What site is the AR site? Let's say I eventually find a tripler. Would there be anything worth doing to coat the housing for further longevity?

I tried sending a PM to the user that bought an ECG561 to confirm that it worked but hadn't heard a response. Just one discussion here is the only evidence I've seen that this is the cross reference part.

Yes, unfortunately it's that 5 terminal one.

AR site:

https://antiqueradios.com/forums/index.php

jr

great, thank you

Like a nutjob, I snagged what I believe to be the correct paperweight to go with my giant paperweight. Joking aside, I remain committed to finding the tripler and getting this set working again. Here are some pics for the curious. I thought it was kind of funny how the PCB interfaces with the buttons with the same push-on connectors as the modules in the set. I can hear the power button, channel hi, zoom, and volume buttons. My phone registers the tones as being upper 8khz to mid 9khz. The other buttons seem to do something as my mic gets overwhelmed and shows 100db of all frequencies when I hold the remote right up to the mic with buttons pressed. Might be outside the response of the mic. I won't be able to test beyond this till I can power the set up again.

It's half tempting to fire this up again to see if I can witness what exactly went. I hate to break more things. Maybe worth disconnecting the flyback from the tripler to isolate that as being problematic? I have feelers out for a tripler but so far no luck.

Side note, I get 10ohms across the oil capacitor, but with it still in circuit.

https://lh3.googleusercontent.com/pw...cAWlLsfHM=w600

https://lh3.googleusercontent.com/pw...QCnO6---g=w600

https://lh3.googleusercontent.com/pw...kCNMgM0FE=w600

https://lh3.googleusercontent.com/pw...4arbXiLoY=w600


Here, I noticed the ground strap from the aquadag cover (is that what we'd call it?) to the power supply board was baked by an adjacent wire wound resistor. The insulation is crispy now, but I pushed these apart from one another. Guessing this isn't of much consequence, but thought I'd throw that in here.

https://lh3.googleusercontent.com/pw...pUSDQMflc=w600

As an update, I managed to find a NOS ECG561 tripler for a fair price. I still don't even know 100% that is crosses, but the appropriate amount of terminals are there. Do these hold up any better/worse than Zenith parts?

I just applied silicone to the input pin and will wait until tomorrow night to try powering it up.

As a side note, I managed to snap in half the clip that covers the focus and control pins when trying to reinstall it. I figure nothing is done without a reason, should I silicone these wires given that the cover broke?

https://lh3.googleusercontent.com/pw...6KiWmava4=w600


https://lh3.googleusercontent.com/pw...YPeMwofkc=w400


https://lh3.googleusercontent.com/pw...2tL5WUCzs=w600

Intriging, this remote control is sonic (audible) or ultrasonic system? In case of ultrasonic, the ultra small MEMS mic from cellphone can be confused with high amplitude ultrasonic signal.

Zeniths ran somewhere between 30k & 40K. Ultras went away
apx 1980. they got them to the point of having full key boards with
near 20 buttons & made them very reliable. I dont remember any being
triggered by random noise like shaking you keys or the dog scratching his neck !
Zeno:smoke:

Interesting!

Alex,

I'm guessing that the tones that I'm hearing and that my phone can pick up are a harmonic from the actual tone. The screen over the transducer is pushed in a little bit, maybe that's doing something.

At any rate, I assumed that the plastic clip that I broke is just for mechanical stability of the connections, went ahead and covered those in silicone as it'll lend to that somewhat.

I powered the set up at 60v and got snow on the screen, brought it up to 80v. All the functions of the remote work as they should. Then I thought I'd go ahead and shut it down for a while and savor the potential success for a while before pushing my luck further : P I didn't hear any arcing so far.

A little though of this curious subject...
Maybe, depending on the model, it are outputting audible tones with ultrasonic hardware, when it emits 2 ultrasonic tones (2-tone mode, but I dunno about models using this scheme), and it intermodulate. 8kHz audible can for eg. significate a 30kHz and 38kHz making a IMD difference tone.

Quick question- are the plastic coils for the convergence supposed to run hot? I was trying to get some adjustments made, probably had the set running for an hour. Noticed the slightest amount of smoke coming from the area of the L601 convergence coil (for blue horizontal lines on the left side of screen). I shut the set off and found the surface to be 145F with an optical thermometer.

The coil below it, L603, was seized up, but it seems that the heat from operating has freed it up, so I guess that's nice.

I feel like I am at least making some headway, getting an idea for how the pots correspond with the grid on screen. Purity is out of whack now, so I have to circle back to that, but at least I'm a little less jumpy around this thing. Once every once in a while, I head an arc or two snap when powering the set on. I'm still trying to figure out where that could be. It's pretty quiet in operation. Actually, the CRT doesn't seem to whine like it used to when I put a grid or dot pattern on the display. Would a new tripler be why?

Also, how are these ECG triplers? Are the failure rates similar to original?

Back! 2 days after my last post, my second daughter was born. I'm starting to find the odd moment here and there to circle back to this. At least through a facebook tv repair group, the general consensus was that the convergence coils run hot.

What I'm trying to do now is to set up the color purity. This looks so easy on youtube videos of 1960's delta tvs, but holy cow, things are cramped on this vertical chassis! I'm only able to move the deflection yoke about half an inch forward or back, so I'm not getting a great view of what exactly is going on when I move one ring or the other. Any pointers here? (like does one ring move the spot up and down vs left and right) I can get the red region mostly into the middle of the screen, but it's not a nice round spot. When I push the deflection yoke in, I'll still be left with a little green or blue in a corner. SAMs photofact doesn't dive into this much. Thanks!

Purity rings behave the same as centering rings on a monochrome TV...If there's only one tab on each ring then when the rings overlap they cancel each other out and at maximum spread have maximum shift in one direction that you can rotate by moving both rings at once in the same direction.

If you can get a service degaussing coil or make one from a scrap BPC TV (as I have a sticky on somewhere here) it's a good idea to manually degauss before going through the purity process as sometimes the screen can get magnetized bad enough that the internal degausser isn't sufficient.

If yoke travel is limited and you can't get good red spot, adjust for best centered red you can slide yoke forward until the screen isn't underscanned and you find the spot with minimum impurity (it doesn't need to be maximum forward in operation), then if necessary tweak rings to eliminate or minimize impurity.
I've had at least couple of sets where yoke travel made the by-the-book purity adjustment process impossible (was able to get through it by feel and screen educated guess work)...If there's bad enough screen magnetization you'll never get it perfect or have a very long manual degauss ahead of you...Some sets only need a degaussing.

BTW you can undo some angle braces at the sides and hinge the chassis down and away from the CRT to get better access if necessary.

Very informative, thank you! I have things closer yet, but not still not great. Best result, with no underscan even, seems to be with the yoke mostly pulled back. Everything goes way out of whack when moved forward. I'll aim to get hold of a degauss coil before really beating myself up on this further.

Side note- the purity ring/blue lateral magnet setup on this set is so weird, rings are inconveniently behind the magnet, very hard to get hands on. I'm about 99% sure it's not on backwards either. The magnet adjuster faces forward.

https://lh3.googleusercontent.com/pw...Dvwucz5Mw=w600

I don't know what that TV is supposed to look like inside, but it almost seems like that's on upside-down, not backwards. You'd be able to grab the rings if the magnets were facing down.

Hopefully someone (Zeno?) can comment on it.

The job and kid situation has really been making hobby time near impossible to find! However, I've been motivated to really come back to this and make headway since I restored a mid-80's linear stereo VCR in the meantime. I got the color purity set pretty good a few months ago, and then started trying for convergence just recently. I feel like I have a handle on the process- going the rotation of steps in the SAMS, touching up the center as necessary. However, I'm just not getting there. This isn't a matter of trying for perfection, it's just that there doesn't seem to be enough adjustment to converge reds and greens anywhere close to decent at the top/bottom/sides.

https://lh3.googleusercontent.com/pw...UTQrAb0lU=w600

https://lh3.googleusercontent.com/pw...L3kkmW2U=w1000

Today, I decided to pull the convergence neck board out and start checking components. I desoldered all of the pots and checked them. They all seem pretty good. 2 of the 300 ohm ones only go up to 290ohm at either end, but nothing seemed to be a failed part. They all did influence things on-screen. (as did the 3 transformers) I mounted them back up and that's essentially there I'm at now.

I DID see that a maybe 1/2w 330ohm resistor looks to have gotten hot, making it a little hard to identify the colors, It's measuring 390ohm in circuit. Maybe that's a sign that I should consider replacing all the presumably carbon comp resistors on the board. The SAMS is missing the resistor list, guess that'd have been too easy, but I should be able to do my homework and ID them.

Is there anything else on the board, or otherwise, that I should be looking at that could be making it impossible to get moderately close to good convergence? Thanks for reading along!

If the convergence diodes are all in a milti-pin module they're probably selenium and could be bad. Also if the convergence yoke isn't lined up right on the neck that can cause issues.

Thanks! It looks like I've got 13 discrete diodes all over the convergence board. I'll have to lift an end of each to check them out, on the to-do list while I have the board removed.

My first thought was also the yoke. I've had convergence issues that turned out to be purity issues and vice versa.

Assuming all your diodes are checking okay and nothing it obviously wrong, you probably want to start from square one and reseat the yoke etc with best purity and everything in the middle