A few OEM-NOS RCA parts distributors. I dont know who they are sry.
For them you need the 6 digit RCA part #. Format is ######. It probably starts with a 2. Also have the FULL chassis # & the designation of
the IC ( such as IC### ) from the PCB just in case.

Alt is pull the old IC & get the generic numbers off that IF it has any.
Also if the IC got real hot the numbers can fade away. They can be searched
for & often subbed to a replacement line such as TCG.

73 Zeno:smoke:
LFOD !

Ty 👍

RCA part number is 215531 or tda8172
i probley have some of them

How much for it if u do?

I might even have some of the Parts you need for your TV in my parts stash, a few years back the local Salvation Army Store (before they closed up shop for good during the pandemic) had a couple of baskets full of old electronics parts that came from a local appliance repair shop that went out of business because the owners passed away, in that basket was a bunch of RCA, Zenith, Magnavox (NAP) ICs for TVs and VCRs.

i think i have a new 27'' ctc203 chassis i will look and see.

Cool. Let me know.

Did you get the parts i sent you..

Yes, I'm gonna be putting in soon. I was hoping to replace entire chassis but idk.

Got the ic switched out today and found the 100ohm 1A thermistor just laying on the board next to the fuse. Does anyone have one? I might have one laying around but I doubt it. Usually have everything but what I really need.

Those degaussing thermistors fell apart on many brands. I used to just solder the wires back on.

U mean the disc back on the 2 wires?

Ok, new ic put in. Finally got everything back in and tried it out today. Focus keeps going in and out about every second. Never seen that before. Also was surprised to see something called warranty clock. Ne ver in 40 years of working on tvs have I ever seen something like that. Kinda cool. Says has operated 65,000 hours and was first turned on 4-11-2000.

That focus problem can be caused by a broken/loose connection in the focus circuit. Anywhere from the flyback, focus control, CRT socket, or CRT focus pin.

That tube looks weak from that pic... Hopefully it will balance out when run a few hours.

Focus drift can be coming from anywhere, including the CRT itself. Sometimes in a quiet room you can hear the arc beat in time with the focus drift. A rubber tube probed around might tell you where the drift is coming from.

The focus drift is probably coming from inside the CRT socket assy or (yikes) behind the socket guide. Given the history of this TV being outside, the possibility of it trapping moisture from the air inside the socke, behind the socket guide, or inside the flyback is very real.

The CRT socket assy has a built in spark gap to ground out any wayward internal CRT arcing to ground so as not to back up into the kine drive circuits.

The assy is normally held together with melted "rivets" that can be easily removed. Carefully separate the halves being careful not to let the individual metal pins get away. You will see the spark gap inside, and if it's been arcing, you will see some greenish smutz in that area. Cleaning won't help but with a Dremel and a fine tip, you can grind out the arced area leaving fresh white plastic. Go over it with a bright light and magnification and make sure to remove absolutely all of the green smutz.

If inside the socket is clean, the problem might be between the plastic guide pin and the neck of the tube. When these were made, most of those guide pins were pushed on and held in place with clear RTV. If it's glued, it's hard to get behind. If you try prying to help, use a plastic spatula instead of a metal screwdriver. If you get the guide off, look for that same green crap behind the guide (if it's white - if it's black, you won't see it). A replacement guide is best but you can try soaking the guide in ISO for a while and brush it out. Clean the neck of the tube and carefully remove as much RTV as you can. I wouldn't replace the RTV however.

A third option is the flyback itself is arcing internally at the focus divider/adjustment. If so, you might be able to hear it with your rubber tube stethoscope. You can try removing the fly and putting it in a box with a hair dryer blowing into it on low for a few hours and hopefully drive any moisture out.


John

Funny enough, this is the first time the focus has done this. All the other times it never did this. The inside and back has never been wet. I'll go back in a couple days and look everything over again. The tubes not as bad as the pic shows. My camera on my phone messed up awhile back and now mostly everything I take a pic of doesn't look all that great. Also need to check my connections inside. I might have left something unplugged as the left speaker doesn't have sound.

https://youtu.be/tBHlg-NCjQo

I put a video up on you tube showing the focus. Seems like speed of flicker depends on what's being show on screen. Sometimes it speeds up and sometimes it slowes down.

Have you listened for it? That type of focus pulsing is often audible as well. In a dead quiet room, listen for a soft pop in time with the focus change. If you have a HV probe, you can measure the focus voltage right at the CRT pin. You will have to refocus with the meter in circuit.

John

Unfortunately, I don't have a probe. I did listen for sound but all I remember hearing was the low hum usually associated with these sets. I will try again when it's dead quiet to see if I notice anything. Only thing that's bothering me is all the other times I ran this set, there was no focus pulsing. Could it be something caused from removing the chassis last time , transport of the board from a to b, and when I put it back in?

Pulled it back out today and tried everything I could think of. Listening for a tick or any sound in timing with the pulse but nothing. Someone said I should try running the focus back and forth on the flyback. Does that seem feasible?

I give up. My whole goal here was to save crt sets from ending up in the dump. I got close with this one and now it looks like this :(

That could be a corrupt eeprom. These chassis *must* have the tuner grounds soldered and the two heatsinks tabs - the horiz output and the LV regulator.

Not soldering these grounds will absolutely corrupt eeproms. I remember changing an eeprom in one of these in warranty for no audio. Two days later it was back. These chassis were new at that time and we had little experience with them. A call to RCA about the failed eeprom was to solder the tuner and heatsink ground tabs. RCA issued a "goldenrod" about this about a week after I ran into this.

You could solder the grounds and then get into the service menu and reset the vert height and centering. Normal values are between 0-63 IIRC but sometimes we'd see values that didn't make sense, like numbers in the hundreds or with letters instead of digits.

John

Hey John. I turned it back on and it's running normal again. Should I go ahead with the grounds?

The TV may be working normally now, but the next time the ground connections come loose the problem will return and could corrupt the EEPROM chip. I am no expert on these by any means; I only worked on TVs, the old tube-operated ones, as a hobby years ago (my basement was full of them, trash finds, in the '70s) and have absolutely no experience at all with modern solid-state sets. Your best bet would be to look for someone who is well-versed in this type of repair, but as I said, I would at least try resoldering the grounds; this may get the set working again unless the EEPROM chip was damaged by static charges, etc., in which case the only solution would be to replace the chip. In a TV this old (23 years), it may not even be worth repairing; in fact, some repair shops may not even touch it.

The grounds should be done in any case. Your eeprom isn't corrupted because they don't "fix" themselves when they are.

It would be the tuner grounds specifically that are causing your issue with the picture even when using AV inputs. The ground to the jungle IC runs through the tuner (stupidly).

The tuner is a surface mount affair and is delicate work. You have to remove the tuner cover (soldered down) and then solder the tuner perimeter and several ground pins in the middle of the tuner.

There is an alternative if you don't plan to use the tuner - solder a ground wire from the cage around the micro and jungle IC and bypass the tuner directly. I've never done this but if you want to try, the point you need to solder your wire to would be on the lower right corner of the tuner when the board is oriented where the tuner input connector is facing straight up. There is a ground point that has a wire soldered to it on the top side of the board.

John

Ok, in a couple days, I'll get in there and get that done. I mostly use the av and s-video. While I have the board out, would it be advisable to do a "board wash"? It's really filthy.

I wouldn't unless there's a sticky grime that on the board that you can scrape off with your fingernail.

I used to wash boards in the old days strictly for aesthetics. But I would remove *anything* on the board that could trap water. In your case,that would be the flyback and SMPS transformer and any tunable coils, but I don't think your chassis has any.

My favorite solution was a product called Parson's sudsy ammonia (I don't know if it's still around). The boards would come out so clean they'd literally shine.

I had a hot box built with a small hole to put in a low temperature hair dryer snout and a hole on the top of the box. They'd dry for at least an hour before going back into service.

John

Alright. If I do, I'll heat dry it, then it'll sit for a few days just in case.

Cleaned up everything real good. Everything done but tracking down the focus issue. I'll be getting a probe soon so maybe that'll turn something up. Everything else looks good. I do have one other issue. Only the speaker on the right side is working. Nothing from the left. Going through the audio settings in menu changes nothing.

When the grounds act up, they typically cause bit corruption in the eeprom (more often than not). Since there are no mechanical adjustments except F and G2, *any* adjustment including tuner alignment can be tweaked off.

First, go in the customer menu and see if the TV has a balance control. If it does, move it far left or far right and make sure it stops at either extreme. Often, the pointer will run through the stop and appear on the opposite side. Keep moving far left or right until the pointer gets "locked" inside the ends of the balance range. The pointer can often run through the stops several times before you get it centered. That might fix it.

John

I found the balance and ran it left and right. Stops where it should. All the way to the right, I have sound. All the way to the left, nothing.

Sound problems other that corrupt eeproms are uncommon in these. For the heck of it, did you verify the speaker itself?

The 169s had issues with leaky caps making the boards conductive and upsetting the audio output ICs causing int sound, squeaks, squeals, and no sound, but I never saw any later RCAs do that, but on the other hand, these are another ten years older, so...

John

No but I have thought about it. I'll get one tomorrow for and put it in there to see if it'll work.

I've yet to try the audio on this thing. I have a pair of speakers from another set I will try. I've been thinking about the whole focus issue lately. It doesn't start messing up till it warms up. Could it be caps and which ones? I'm thinking on changing some out.

I doubt it's a cap. That type of focus error (absent of any other picture symptoms) is going to come down to a bad flyback, a bad CRT socket, or a bad tube.

In the order of probability, I'd put the socket first, tube second, flyback third.

John

So the part of the board that slides onto the pins of the tube. Can I check that in any way? I know this thing has some hours on it. Counter says 65000. And I just found out that left speaker was bad. Changed it out with another and is working now.

Not easily (pics?)

The problem is that many of these develop a green coating inside the socket assy that becomes resistive (not measurable) over time and humidity.

Back when they were new, we'd order a new socket. When they got harder to find, I'd take them apart. They're usually held together with melted plastic posts. I would drill them out and carefully separate the front and back half.

if there was green (or worse) tracking between the Focus pin and the ground pins (there's a built in arc-gap in there), I would get a Dremel and carefully grind out the contamination like a dentist would remove tooth decay. Clean with IPA and dry well.

If it was repairable, I'd reassemble with a couple of well placed drops of RTV where the plastic posts were drilled out.

John

Oh nice work. You want pics of the screen or the socket? Probably the socket....

There's a chance I may have that socket. Give me a couple of days to check through my buried pile of old crap.

There's also a chance that the cover over the focus pin may be removable by unsnapping the little fingers that hold it together. If I can't find a socket, we'll try looking under the hood so to speak.

John

Ok thank you :)