I just got this TV because I liked the simple cabinet. I assume it's from around 1972-73 but I have no way to tell... I haven't tried to connect it yet as it was stored in a cold place but I'd be surprised if it works.

I don't have electronic skills or equipment but I'd appreciate if I could get some advice before I attempt to connect it! The previous owner told me he got that with a house he bought and he also told me he connected it. And that it "worked" as he could hear sound and see the picture tube showing snow but I didn't trust that.

The power cord was cut and his son had just attached a new cord to it and was ready to test it at 10°F! I told them not to try it, that i'd take it anyway at a lesser price as I was pretty sure at this point there was something wrong with it! I removed every screw that was holding the back panel by hand so someone has been there and for some reason, didn't fasten the retaining screws as if the repair job wasn't done!

I heard that some RCA chassis from this period (or maybe a bit older) weren't too good and had a lot of flyback problems. Is this one among them?

A few more pics...

I plugged it and I do get sound and snow as the seller told me (I really didn't expected that!).

But the image won't stabilize on channels 3 or 4 with the converter box. I'm not too familiar with the controls and adjustments on this TV.

I wish I had more technical knowledge but I think I'll need some help with this!!

There's a screw to adjust each of the VHF pushbuttons and there are 4 UHF presets that can be tuned by small knobs hidden behind the panel. There's another control which says "fine tuning pull" below that door and it can be pushed for "accutouch". What's that, I don't know!

Here some larger pics.

https://www.flickr.com/photos/33723086@N02/sets/72157650024076848/with/16345745712/

Never seen one. Looks like an updated & common CTC38.
On CRT the 72-52 means 1972, 52nd month so set was built early
1973.
For tuning I will give you the most likely process, maybe
one of the RCA pros knows for sure.

Hook up box.
Press ch 2 button
Turn off any controls marked auto or accu.
Now the ch 2 control should tune from ch2-ch6 or ch2-ch13.
Usually ch 2 will be almost full CCW. Tune the knob CW till
you see a color picture. The knob can be turned many times.
The meter is marked for UHF but should also read VHF, you
can watch that to see how you are doing.

You are off to a good start, the CRT looks very strong.
Good luck

73 Zeno:smoke:

i had this same set about 25 years ago.very good performer with a top of the line rca crt.was a watcher for a couple of years and worked flawlessly.the tuner was a little touchy but once i got it set,it was fine.your crt looks bright.that one will take many hits if needed.good score and this is a fairly rare set

I'm surprised that you are so surprised that it works. I've had early 50's TVs that have not been repaired since the late 60's, and not powered on for over a decade wake right up and work, and I sort of expect most 1965 and newer sets to work, or come very close.

See what you can do with the fine tuning as a first step.

I connected a DVD player to it and I was able to get sound. It also displays an image but not too good! No color most of the time and when it does...

I also noticed that the contrast knob doesn't turn...


That's the best I can do for now.

Horz phase is off & tint looks all the way to the green.
That may be one problem or two different problems.
Contrast probably needs a drop of WD40 on the shaft.
If you dont know TV already its time to do some learning
& get a sleeve of 6GH8's !
Not to worry, we all will help.

73 Zeno:smoke:

A SMPTE color bar pattern will show tint misadjustment, and is a good calibration reference. You can probably burn such a pattern to DVD without much issue.

If the set uses a 3-legged dual diode for horiz phasing, that is the most likely suspect.

Does the tint control have any affect at all on that 'greenish' component of the pic? If not, turn the color control all the way up & down, and see if it varies amplitude of the greenish component. If so, that suggests the 3.58 oscillator is not running (the greenish component being chroma information minus the 3.58 reference signal). Try wiggling all the tubes in their sockets on the chroma board. Corrosion in tube sockets often causes all kindza problems. Then test or sub the 3.58 osc tube.

Where exactly is that 3 legged diode? is it welded to the board? The horizontal adjustment certainly has a problem... The Horizontal Hold is very sensitive and won't center the image...

Look at the image from the video. The color goes out as soon as the tuner is set for a clear image (if the Accutouch control is pushed, the image stays in black and white...).

I turned the tint knob while the recording this video. It does affect the colors but they can't be set correctly...

http://youtu.be/5YwrNCDaZ4M

OK, the 3.58 osc ('color oscillator') is running but out of sync.
The 3-legged diode, if used, will be close to the H oscillator. But try adjusting the AGC first, if you haven't already. Have you tested/subbed any tubes yet (with emphasis on the sync and AGC tubes)?

Once you get this TV working as it should, it should serve you well, as this is one of the original RCA sets from the '70s. You will still be able to use the VHF and UHF tuners, as Canadian TV, albeit mostly digital since last year, still has many analog channels still operating, unlike here in the US, where analog was done away with in 2009. I don't know what Canada's future plans are, if any, as far as "repacking" the TV spectrum are concerned (as our FCC is doing in the US), but until or unless they do follow our lead and eventually go 100 percent digital, you can use your RCA CTC-38 just as it is; just connect an antenna and enjoy it, just as you did before some Canadian stations went digital.

I don't have any testing equipment. (other than a multimeter!). I wish I had the schematics but I couldn't find that exact chassis model on SAMS photofact. Most CTC-39 chassis seem to have an "X" after the "39", mine has a "V" instead (at least, that's what's clearly stamped on the flyback cover).

Maybe I don't need the exact model but...

I'm really not familiar with TV sets. I haven't touched to the AGC, I have located the control at the back but I don't even know what it is for (I know it means "automatic gain control" but I don't know what that means!). I don't want to sound stupid but I'm really missing some basic understanding and I can't find the most basic information on internet! I have seen videos of people rejuvenating picture tubes, making adjustments, testing the high voltage but I was missing the more basic things... I wish there would be detailed explanations on how to service old TV sets on internet but I haven't found anything for people who also need to get the basic knowledge. The most complicated electronic job I have done so far was replacing 3 capacitors in two microwave ovens which had display problems... That fixed the problem but I went from instructions that I found online, not from my own diagnostic!

I don't even know what the service switch is for at the back of the TV! I noticed it has 3 positions but I didn't try anything that I don't understand by fear of causing other problems... I also have been electrocuted when playing with an old tube radio when I was a kid and I'm careful not to touch anything in TV set. I don't even know what has the potential to shock you! I know most users of this forum are experienced but I'm not! I'm fascinated by these TV sets since I was a kid but couldn't ever find somebody to explain me how they work in detail!

Yesterday, I went to the only place in town that repairs electronics. I went there years ago with my Pioneer SX 800 receiver and when the guy noticed it had tubes in, he told me he couldn't service it... I guess he knows how but he's not interested at all. I just asked about the TV and I got the same answer... Needless to say there's not a lot of action in this store, as people don't care about having newer stuff repaired anymore!

Jeffhs, there isn't much remaining on the analog spectrum in my area. The last time I checked, there was just one station with very poor reception, I couldn't even tell what it was or where it was from!

I do have a Channel Master converter box and a RF modulator to plug a DVD player. I don't watch TV but I still want mine to be working again!

And the chassis is a CTC-39VA, not 38.
BTW,
Can somebody tell me if RCA had a similar model with a pushbutton tuner available in the US and what chassis number was used? All the documents I have seen so far seem to feature sets with rotary knobs. I didn't find the 1973 brochure and I think the 1972 brochure I saw was just featuring the Solid State models.

Think of AGC as a sort of automatic RF system amplification factor adjustment. Basically a TV is a video monitor with a fancy radio attached. The video monitor portion expects the video signal along with the synch pulses and color information it contains to be one specific amplitude. The signal the monitor half gets from the video detector at the end of the receiver portion would naturally vary in amplitude in step with received signal strength if it were not for the AGC. AGC controls the receiver gain so that the signal out of the video detector is the same no matter what the signal strength at the antenna is. How it usually works is by measuring the level of the horizontal synch pulses and comparing them to a fixed reference, and generating a error voltage that is sent to the tuner and IF stages to adjust their gain so that the error goes away.

Look for a block diagram of a color TV set with explanation of the blocks, it will help you understand what is going on.

Edit: I don't think we sold tube sets with that style of tuner. It should not matter if the tuner section is right because most sam's did not explain how to change the dial light, or clean the contacts which are about the only service procedures someone without a LOT of experience and specialized RF/IF alignment equipment has any business doing to a tuner.

Thanks Tom for the explanation! I'll look for that!

But can I just turn the AGC screw and see what it does to the picture without any test equipment connected?

Tom, the tuner section seems OK but there are some burned lights in the pushbuttons (one on Channel "6" and on the "B" UHF channel which I won't use but...). I wish I also knew how to access them!

I just noticed that I've been following you for years on YouTube. You're partially responsible for having me posting here! I did get several emails from YouTube showing some of your TVs. I started to follow you because one of your videos featured a Frigidaire washing machine (I also collect old appliances, mostly GM Frigidaire, at least, I'm able to repair these!).
I know you sold that Frigidaire washer but I think there should be at least two other appliance collectors here!

I don't have any testing equipment. (other than a multimeter!). I wish I had the schematics but I couldn't find that exact chassis model on SAMS photofact. Most CTC-39 chassis seem to have an "X" after the "39", mine has a "V" instead (at least, that's what's clearly stamped on the flyback cover).

Maybe I don't need the exact model but...

I'm really not familiar with TV sets. I haven't touched to the AGC, I have located the control at the back but I don't even know what it is for (I know it means "automatic gain control" but I don't know what that means!). I don't want to sound stupid but I'm really missing some basic understanding and I can't find the most basic information on internet! I have seen videos of people rejuvenating picture tubes, making adjustments, testing the high voltage but I was missing the more basic things... I wish there would be detailed explanations on how to service old TV sets on internet but I haven't found anything for people who also need to get the basic knowledge. The most complicated electronic job I have done so far was replacing 3 capacitors in two microwave ovens which had display problems... That fixed the problem but I went from instructions that I found online, not from my own diagnostic!

I don't even know what the service switch is for at the back of the TV! I noticed it has 3 positions but I didn't try anything that I don't understand by fear of causing other problems... I also have been electrocuted when playing with an old tube radio when I was a kid and I'm careful not to touch anything in TV set. I don't even know what has the potential to shock you! I know most users of this forum are experienced but I'm not! I'm fascinated by these TV sets since I was a kid but couldn't ever find somebody to explain me how they work in detail!

Yesterday, I went to the only place in town that repairs electronics. I went there years ago with my Pioneer SX 800 receiver and when the guy noticed it had tubes in, he told me he couldn't service it... I guess he knows how but he's not interested at all. I just asked about the TV and I got the same answer... Needless to say there's not a lot of action in this store, as people don't care about having newer stuff repaired anymore!


The letters AGC do, in fact, stand for "automatic gain control"; the control on the rear chassis apron of your TV sets the optimum operating point of the AGC system, which prevents wild variations in contrast, etc. under varying signal conditions. Setting the AGC threshold control too high will kill the picture; setting said control too low will result in a weak, washed-out picture. In most areas, the optimum setting is in the middle of the control's range. If the TV works, however, I'd leave the control alone.

The three-position service switch is used to collapse your TV picture to a horizontal line across the width of the screen. This is used for checking beam convergence inside your TV's picture tube, or CRT, although for proper convergence adjustment an electronic test instrument known as a dot-bar generator must be used. I'd leave the switch set at "normal" unless there is a good reason for changing it.

The third position is likely "raster", which removes the video input signal from the picture tube; you will see nothing but a white screen with the service switch in this position. I'm not sure what the "raster" position of the service switch is actually used for, although I wouldn't be surprised if some TV technicians in the '60s-'70s were sent out on home service calls for "no picture", only to discover the service switch was set, accidentally or otherwise, to the "raster" position. I bet many nuisance service calls were made as well on sets that showed just the bright horizontal line across the width of the screen (or a blank white screen), when the only "problem" was that the switch had been set to the service or raster position, respectively, perhaps accidentally or even by inquisitive children.

As long as your TV works, there is no need to change the positions or settings of any controls along the back of the chassis; in fact, incorrect settings of some controls can damage or destroy parts of the set. Today's flat screen TVs, and the last CRT TVs made before digital, are designed so that the service adjustments are absolutely inaccessible to the average person; in fact, with flat screens, the service adjustments are set using a special "service" menu which is accessible only to technicians. (My RCA CTC185 CRT TV has such a service menu; I've owned the set 15 years and have never seen it.) The keypress sequence used for accessing these menus is also proprietary information, for good reason: to keep unauthorized persons from fiddling with the service menus and possibly, even likely, causing severe damage to the circuitry.

Finally, electric shock is dangerous and can be deadly. You were wise to stay away from the innards of radios and TVs after your experience with being shocked, although saying you were "electrocuted" isn't quite accurate; after all, if you were in fact electrocuted by high voltage from anything, be it a once-common 5-tube table radio or TV, you wouldn't be here today. The high voltage on a television picture tube is just as deadly if you don't know what you are doing. TV CRTs (picture tubes) have what is called a second or "ultor" anode, to which a well-insulated cable coming from the TV's high-voltage cage is connected. The voltage on the second anode is measured in kilovolts (thousands of volts) and ranges from 15,000 for a black-and-white CRT to over 20,000 for a color tube. This voltage has the potential to stop your heart (at worst) or, at best (!), it will throw you across a room. The warning on the back covers of all TVs, from the very first ones to today's sets, says it all: "DANGER. HIGH VOLTAGE. REFER SERVICING TO QUALIFIED PERSONNEL." Some sets of early '50s vintage had even more strongly worded warnings: "DANGER. HIGH VOLTAGE. DO NOT REMOVE THIS BACK UNDER ANY CIRCUMSTANCES."

This warning did not, however, deter some people from replacing bad tubes in their TVs; in fact, from the '50s until about the end of the '70s, self-service tube testers could be found in drug stores and the like. One of the most sophisticated such testers I can remember was the Hickok "Cardmatic" tester, from the late '50s-early 60s. A drugstore in the next town east of where I grew up had one of these tube testers; it used punched cards to set the various operating parameters of the tube being tested. This tester was made for non-technical people; all one had to do was find the type number of the tube he or she wanted to test find the card bearing that number (for example, 6AW8), insert said card in a card reader on the front panel of the tube tester, insert the tube, and push one button. The condition of the tube then registered on a large analog D'Arsonval meter on the front panel. Tube testing didn't get any easier than that.

Yes it is normally adjusted by eye without test equipment in most sets. If AGC is too low contrast will fade to washed out white, and possible loss of synch. If it is too high you will get loss of synch, negative video contrast too high even with contrast control at minimum.

IIRC the adjustment procedure is usually adjust until high and synch starts to be lost then back down until normal synch and reasonable picture contrast is achievable with the contrast control.

If you can't get synch suspect the synch separator. I don't own any RCA based chassis that new so this advice is from what I've read: RCA chassis with more than two 6GH8 tubes tend to eat those tubes regularly due to bad circuit design*. If any of your problems are in sections that use one of those tubes try swapping the tube first.

*I've read stories here of how something like every month or three service men who had contracts with hotels equipped with RCA sets would literally go around with a shopping cart full of new 6GH8s and change them in every set in the building...Because the sets needed those tubes replaced that often.

EDIT: I can't believe jeffhs slipped that wall of text in under me so fast.

I've been watching 6GH8a tubes on eBay... It seems some sellers are selling them by the dozen (or almost!).

I'll probably buy a few!

Just to clear up Jeffhs fuzzy description of the service switch. The line position of the service switch was not often used for convergence, but rather gray scale adjustment. One would drop the brightness and color controls to min, enter the line mode of the service switch, turn the screen/G2 controls down, increase red until faint line appeared, increase green until line became yellow, increase blue until line turned white, then return service switch then brightness and color to normal positions...If whites looked tinted after that adjustment of color drive controls with a black and white picture would be the next step.

The blank raster position of the service switch could be handy for purity set up if you left your pattern generator at home. Purity with a blank raster can be achieved by turning the blue and green G2 controls down for a red raster, sliding the deflection yoke back until the screen looks tie dye, *centering the red dot using the purity rings, then sliding the yoke forward until the screen is completely red and readjusting the green and blue G2 controls. If you find that need to do a purity adjustment after you get the color demod working right a good short cut is to use a test pattern DVD with a fully red screen to do the purity without messing with the switch or the G2 controls. I find the G2s generally are more stable than purity, and I hate to mess with the G2 once I have them set just the way I prefer them.

*a degauss of the screen before this may be necessary.

There's no way he can hurt anything by turning the AGC control. Given the symptoms displayed in his vid, the first thing I would do is see if the AGC setting affects the pic. And go from there.

I tried, it definitely changed something, but no real improvement... I ordered 5 6GH8A tubes just in case I'd need some in the future (and I think I might have a few used ones already but no way to test them!). and I hope to get some tools.

Another question, I can hear some static noise sometimes coming from the back of the set, not constantly but sometimes. I know most older CRT TV sets I have seen make this kind of noise sometimes and I haven't been able to locate it but I wouldn't be surprised if it came from the flyback transformer (when you're looking at the back, the noise definitely comes from the right side of the cabinet). With all the comments I read about some late 1960s RCA sets having problems there, should I have a look at something or it's normal?

I tried, it definitely changed something, but no real improvement... I ordered 5 6GH8A tubes just in case I'd need some in the future (and I think I might have a few used ones already but no way to test them!). and I hope to get some tools.

Another question, I can hear some static noise sometimes coming from the back of the set, not constantly but sometimes. I know most older CRT TV sets I have seen make this kind of noise sometimes and I haven't been able to locate it but I wouldn't be surprised if it came from the flyback transformer (when you're looking at the back, the noise definitely comes from the right side of the cabinet). With all the comments I read about some late 1960s RCA sets having problems there, should I have a look at something or it's normal?
I pulled the Sams on a CTC39 & its pretty much a CTC38.
Kinda surprising RCA didnt make a hybrid before going all SS.
A sleeve of 6GH8 is a good start. Start with the pair on the
forward board & see what she does. Those two sockets were trouble
also & we changed quite a few.
The noise is probably arcing & usually you get an ozone smell.
Can be coming from focus socket, HV rect socket or wires or
the plastic cup. Flybacks usually melt & short. Sometimes they
burn. Check it for cracks & wax dripping. A little wax is OK
but if its a big pile its a concern.

73 Zeno:smoke:

I thought mine was a hybrid set? I don't see many tubes in the tuner section:

https://www.flickr.com/photos/33723086@N02/sets/72157650024076848/

It is a good idea to discharge the HV before messing around inside the HV cage. There are a lot of good threads on it if you search Videokarma. The HV stores charge even with the set turned off so you can still get shocked by it with the set off. The good news is that unless you have heart problems the charge in the stored in the HV with the set off won't kill you....It will just feel like the worst static jolt ever, and possibly trigger your reflexes to pull away.

All I need to do is to clip an alligator wire to a well insulated flat screwdriver and to the chassis, and touch the anode under the cup with the screwdriver? Right?

An HV probe is better. If you discharge through a resistance (such as an HV probe) there is less chance of bounce back. If you short HV to ground then it will temporarily drop the stored charge, but after awhile it will recover some of that charge....Which is often enough to be worthy of some foul language if you discharge that through your body (ask me how I know). If you use the screw driver and clip lead method leave the clip between the HV connector on the CRT and ground until you are through touching parts in the area of the HV.

A good way to fix HV arcing and corona is to take a damp cloth and clean every surface inside the HV cage. Be careful not to break the wires leaving the fly windings.

Then I need a HV probe!

I spotted a similar set in this abandonned house. There must be some service litterature for these somewhere!

https://www.flickr.com/photos/urbex-022/15066074009/in/faves-33723086@N02/

Then I need a HV probe!

I spotted a similar set in this abandonned house. There must be some service litterature for these somewhere!

https://www.flickr.com/photos/urbex-022/15066074009/in/faves-33723086@N02/
HV probe is a nice to have especially if you get more sets. We
always just shorted the HV out but it does come back, much
less each time. Wont kill you, I got nailed once a week for near
40 yrs.
Being a hybrid is a matter of opinion. To me a hybrid is solid
state except the audio out, hoz out, hoz osc, damper, vert out, &
HV rect. All the low level tubes like 6GH8's are gone. The classic
hybrid is the 4 tube Zenith. Hoz osc, hoz out, vert out & damper.
The abandoned house set looks like the CRT got necked, just
a parts set. I would guess the residents have seen the seedier
side of life, what a dump !

73 Zeno:smoke:

I didn't see the abandoned set myself, I just saw a picture on Flickr...

One thing you may want to try, is switching 6GH8's between different (6GH8) positions within the TV. First mark which one goes where, then try swapping them. This got my CTC38 which refused to synch going, until I could get my hands on some new tubes. Some functions ask more of the tubes than others do, so a weak one may be able to perform one function, while being unable to perform another.

The CTC-38 (and I presume 39) is indeed a hybrid, it contains lots of transistors (the whole IF section, half the VHF tuner, the UHF tuner, etc), as well as one IC.

I think one thing which would be prudent to do, is get your hands on a CRT tester, and check the condition of the CRT, if it checks out well, you have a green light to put some effort into this TV. I have a CTC-38 as my "daily driver", and although it isn't perfect (well, what in life is), it's a whole lot of fun to watch and has given me many hours of entertainment.

I found an ad from December 7th of 1972 featuring the model number of my TV CCC991.

It's strange, there was a 26" solid state model that was less expensive. I guess it depended of the style of cabinet. I would have expected a greater price difference between the tube and solid state models.

http://news.google.com/newspapers?id=DFAxAAAAIBAJ&sjid=4qEFAAAAIBAJ&pg=5833%2C2474873

https://farm8.staticflickr.com/7360/15759752833_57bd06d7c0_o.jpg (https://flic.kr/p/q1CRsr)CCC991 (https://flic.kr/p/q1CRsr) by PhilR2 (https://www.flickr.com/people/33723086@N02/), on Flickr

Price should be lower BUT yours has varactor tuning,
one of the first to have it. IIRC the price difference
between a Zenith 4 tube hybrid & a solid state with
the same features was $75-$100 USD back then.

73 Zeno:smoke:

Zeno, what's the best?... Hybrid or Solid state ?

Zeno, what's the best?... Hybrid or Solid state ?
I like the solid state better. Its more reliable & for me easier
to repair. A matter of what you like.
Your solid state Zenith is much the same as the 4 tube hybrid.
Zenith kept much of the electronics the same til a major chassis
change in 1979. If you could fix yours you can fix any of them.

73 Zeno:smoke:

I suppose Zeno. but i was talking about the difference and now i know i have a quality tv and that's why i will keep my Zenith...I suppose also that i'm going to make some adjustments after racapping my Zenith ....The transistors are easy to change because they are just plug'n'play.. ;) thanks for the information about the difference.

I finally got the 5 6GH8 tubes and replaced them.

A bit better but it will need more work!

http://youtu.be/b9FPPa5_UFY

The TV is still at the repair shop but today I got a spare Flyback transformer for it. I hope it's the correct one for this model!

it looks like this replacement model wasn't coated with wax like the original. RCA copied the improved design from aftermarket manufacturers or they just sourced them? The box says "made in Mexico", see the pictures below.


Here's another ad I found:

The larger version can be viewed in this link: https://www.flickr.com/photos/33723086@N02/16715346560/sizes/o/in/photostream/

https://farm8.staticflickr.com/7643/16715346560_6d7a5212f7_z.jpg (https://www.flickr.com/photos/33723086@N02/16715346560/)
1972-CCC991 (https://www.flickr.com/photos/33723086@N02/16715346560/) by PhilR2 (https://www.flickr.com/people/33723086@N02/), on Flickr

https://news.google.com/newspapers?id=IZkuAAAAIBAJ&sjid=sqEFAAAAIBAJ&pg=4614,1799201

That looks like a great set. I have a CTC-40 that needs a flyback, where were you able to find the replacement for your set?

The TV is still at the repair shop but today I got a spare Flyback transformer for it. I hope it's the correct one for this model!

it looks like this replacement model wasn't coated with wax like the original. RCA copied the improved design from aftermarket manufacturers or they just sourced them? The box says "made in Mexico", see the pictures below.


The wax is inside the red silicone outer cover, and coats the outside of the "tire."

Looks like you got one of the last batch - RCA stopped production on the 113382, 113392, and 119834 in 1983 - your date code is 82244, late 1982 production. I worked at Cain Electronics in 83/84 and we offered both the RCA 119834 and the FLY312 for the 38/39 chassis. When RCA dropped the 119834 ( it still appears in my 1985 price guide at 71 dollars dealer net), Thordarson was close behind. Great find - they are rarer these days!

Cheers,

you need some better video content, get some old show like robin hood or wizard of oz if you don't have a test pattern to use.

At the end of the video looks like agc issue.

I got the flyback on eBay for $18, which I think is a decent price for a part with a high failure rate like these!

Dave, you are right about the video content. I don't have many DVDs and I didn't have an antenna connection where the TV was located. My rabbit ears with a decoder didn't get a single channel!

The image wasn't stable for more than 1-2 minutes after playing with the AGC screw and the colors never got right. There were some noises I didn't like coming from the back of the TV near the HV cage.

Having no test equipment or experience with TV sets and very limited knowledge about electronics. I brought the set to a local TV repairman who still wants to touch these sets!
I don't think he did much to it since he got it but he seemed confident about fixing it with minimal parts and labor...
Back in the 1980s, my parents did buy a few things to him including their first sound system with a CD player (and I remember very well the day he delivered, installed and demonstrated it 28 years ago!). I remember I was amazed to see a flat panel TV on the wall of his store back in 1987. If I remember well, that wasn't sold here but was for the Japanese market. Now, he operates his business at home and I think he still does antenna installations.

Interesting thread, Phil R. My RCA 2000 Colotraks, which were reportedly hated by technicians, need some work, but the work will have to wait for now. Your set is nice - hope things come together to get it working as new again.