RCA CRT TV Flyback?

[NxB]

Got a free 27" tube tv. A cap was blown, I took that off. The hot seems blown as there is B-E continuity in circuit. Pulled that out.

The continuity between the B-E remains. Does this mean the flyback is shorted? How can I make sure without a lopt tester?

Chassis is CTC-187AJ

[PlainBill]

Re: RCA CRT TV Flyback?

Got a free 27" tube tv. A cap was blown, I took that off. The hot seems blown as there is B-E continuity in circuit. Pulled that out.

The continuity between the B-E remains. Does this mean the flyback is shorted? How can I make sure without a lopt tester?

Chassis is CTC-187AJ

B-E short? Tube TV? Ohhh!!! You must be talking about these new-fangled designs with transistors!!!

Most designs I am familiar with have a horizontal output driver transistor, which drives a transformer that drives the base of the horizontal output transistor. The B-E junction of the horizontal output transistor will always read shorted until you remove it from the circuit board.

PlainBill

[NxB]

Re: RCA CRT TV Flyback?

Good to know. So its likely just the hot and the cap(s)

[PlainBill]

Re: RCA CRT TV Flyback?

Good to know. So its likely just the hot and the cap(s)

I dunno. I did most of my TV servicing when they had a dozen or two vacuum tubes in them. I ALWAYS assume a shorted Horizontal output transistor was the victim of some other fault.

PlainBill

[EGuevarae]

Re: RCA CRT TV Flyback?

CRT TV?
Is this thread on the right forum?

[Krankshaft]

Re: RCA CRT TV Flyback?

Replace the cap and the HOT and put a light bulb in series with the fuse if it glows brightly and dims you're ok try turning the TV on if it stays bright you've still got a short somewhere.

If there was still a short the horizontal section would be my focus. HOTs can just flat out die they are a highly stressed component. It is also possible that a flyback with shorted turns killed it too.

As for continuity most HOTs in modern sets have an internal damper diode connected between collector and emitter check the datasheet for the part to see if it has one. It can throw off standard transistor checks. Older TVs had it as an external discrete component not too far from the HOT.

[Innov8tive1]

Re: RCA CRT TV Flyback?

I fixed a 32" RCA recently with a blown HOT and it turned out the flyback was shorted as well. Can't remember the chassis number. After I changed the HOT it still would not turn on but it did not take out the HOT again. After checking all other components in horiz. circuit and determining that my B+ was up to spec. I took a chance on the flyback as I do not have a tester for them. Not sure if we can post parts websites here if they are not cap. related so I won't. But if anyone knows if it is ok I will post it. The flyback was under $30 and for this set (fixed for a friend of my wife) it was definitely worth it.

[weirdlookinguy]

Re: RCA CRT TV Flyback?

I heard somewhere that it is EXTREMELY common for late model RCA's to blow the flyback and take out the HOT with it.

[Krankshaft]

Re: RCA CRT TV Flyback?

I buy my TV parts from Tritronics now known as Encompass Parts since they merged with Vance Baldwin.

http://www.encompassparts.com

I've gotten everything from TV parts to a Magnetron for my Sharp over range microwave there.

Another reason why I buy name brand electronics so I can find parts there.

According to your chassis number the original flyback part number isn't available however there is a replacement part number 215539 and it's in stock for $29.00.

Of course I just did this by the chassis number make sure to look it up by model to double check.

[Innov8tive1]

Re: RCA CRT TV Flyback?

I guess it's ok to post links to supplier sites. I got the last one from www.electronix.com
I think, much like caps, manufacturers of CRT tvs likely used poor quality wire with thinner insulation which breaks down and causes shorts. But yes, I have also heard that it is VERY common for newer RCA (among other) TVs to have really poor quality flybacks which take out the HOT.
I don't know if any of you have been servicing TVs for years but I remember Hitachi TVs of the mid to late 80s had terrible flybacks but they didn't take out the HOT as often. With those you could run them on a variac at about 80-85V just enough so it would fire up but not enough that the protection cct would kick in and shut it down. Within a few seconds you'd have a crater in the side of the flyback and a shop full of smoke....back then I trained with a tech who would set one up, flip on the switch on the variac and bugger off to go for lunch, leaving me with a smoking TV on the bench! A real joker.

edit: just checked the electronix site and they have the above mentioned flyback for $18. For the record I have purchased one from them and it worked fine.

[NxB]

Re: RCA CRT TV Flyback?

Yup, flyback gone. Not worth fixing as nobody will pay more than $25 for a tube tv here.

[Innov8tive1]

Re: RCA CRT TV Flyback?

Aaaaaand another piece of electronics hits the landfill...........I'm sure someone would pay more than $25 but you might wait an awfully long time for that person to come along. If I had no tv and the only option was say a $50 tv, I would probably take it.
I find it really sad that it is this way........a set that 10 years ago was well worth fixing and might have brought $150 is now worth nothing.

[PlainBill]

Re: RCA CRT TV Flyback?

Aaaaaand another piece of electronics hits the landfill...........I'm sure someone would pay more than $25 but you might wait an awfully long time for that person to come along. If I had no tv and the only option was say a $50 tv, I would probably take it.
I find it really sad that it is this way........a set that 10 years ago was well worth fixing and might have brought $150 is now worth nothing.

That IS one way to look at it. Personally, I'm happy that I will never again have to unsolder a flyback or replace a shorted HOT.

The other equation may be more to your liking. $125 for a non-working 50" plasma, $60 for main control card, $20 for a remote, 2 hours of labor = $500 TV.

The bottom line is that as long as people look forward to discarding two year old toys so they can buy one with the latest features, a skilled technician can make a few bucks.

PlainBill

[Wrog]

Re: RCA CRT TV Flyback?

Yup, flyback gone. Not worth fixing as nobody will pay more than $25 for a tube tv here.

Consider fixing it and donating it somewhere (Goodwill?). Then someone will surely buy it and you can take it as a deduction (assuming you itemize).

[Innov8tive1]

Re: RCA CRT TV Flyback?

That IS one way to look at it. Personally, I'm happy that I will never again have to unsolder a flyback or replace a shorted HOT.

The other equation may be more to your liking. $125 for a non-working 50" plasma, $60 for main control card, $20 for a remote, 2 hours of labor = $500 TV.

The bottom line is that as long as people look forward to discarding two year old toys so they can buy one with the latest features, a skilled technician can make a few bucks.

PlainBill

I have no problem de-soldering a flyback every now and again and I do realize the benefits of newer technologies but I'm just thinking about all the cheap electronics filling up our landfills.
I actually got out of consumer electronic repair 5 years ago because I was getting increasingly frustrated with the sheer volume of disposable junk and frequent model changes with no parts or service info. to work with. I now enjoy electronics again as I can do it on the side but pick and choose what I work on.
Don't get me wrong, I definitely see your point but I'm looking at it from a different perspective.

[PowerAmpFreak]

Re: RCA CRT TV Flyback?

In older days I repaired LOTS of CRT TV on professional basis. Most common failure was flyback transformers and HOT's. I would say I prefer that way of working on component level instead of more or less module replacement level which is the case with many of the plasma's I've been involved with lately.
And besides, many modules are not repairable, due to obsolete IC's or BGA's.
Back then, there were just one thing that made a CRT repair not worth it - faulty CRT tube which was the case sometimes but not very often luckily.
I know this is quite off topic with respect to the thred, but worth saying.

[Innov8tive1]

Re: RCA CRT TV Flyback?

In older days I repaired LOTS of CRT TV on professional basis. Most common failure was flyback transformers and HOT's. I would say I prefer that way of working on component level instead of more or less module replacement level which is the case with many of the plasma's I've been involved with lately.
And besides, many modules are not repairable, due to obsolete IC's or BGA's.
Back then, there were just one thing that made a CRT repair not worth it - faulty CRT tube which was the case sometimes but not very often luckily.
I know this is quite off topic with respect to the thred, but worth saying.

I definitely agree with what you are saying here. TVs have gotten VERY complicated and aside from a few with "common" problems, they are much harder to troubleshoot..........and forget about tracing a circuit with multi-layered boards.......even if you could trace a circuit, you can't even de-solder or re-solder an IC without some very expensive equipment and a whole lotta luck!!

[PlainBill]

Re: RCA CRT TV Flyback?

I definitely agree with what you are saying here. TVs have gotten VERY complicated and aside from a few with "common" problems, they are much harder to troubleshoot..........and forget about tracing a circuit with multi-layered boards.......even if you could trace a circuit, you can't even de-solder or re-solder an IC without some very expensive equipment and a whole lotta luck!!

This is the same rhetoric that has been around since Lee DeForest. I's sure some radio engineer bitched about the 'new-fangled vacuum tubes in transmitters'. After all, all you REALLY need is a high frequency AC generator - a good mechanical device. It would be sometime in the 1950's that the local radio repairman complained PC boards were unrepairable - his soldering iron caused the lands to lift off the board. And it's been the same thing about transistors, integrated circuits, surface mount devices, hybrids, and whatever the new technology is for 2020 someone will complain they can't fix it. Heck, right now someone is complaining it's too hard to fix 3-D TVs.

As far as troubleshooting goes, I made this problem harder than it was. The service manual was poorly organized; once I found the proper section, the full information was there. As I recall, 1 16 pin SMD chip, 2 8 pin smd chips. The only expensive equipment required for the repair was a soldering iron, Chip-quik, and solder wick. True, in a factory authorized shop I would have probably been forced to replace the small signal board.

PlainBill

[Innov8tive1]

Re: RCA CRT TV Flyback?

You may be right about that but there used to be TV/stereo shops all over and now you have to take or send anything to a big city to get it worked on. There are still some guys (myself included to some degree) who still do a bit of it but it seems that many of us have not kept up with any of the newer technologies. I realize it is possible to do surface mount without all the hot air tools etc. as I have done some, the first being a processor IC for the display on my old Technics SA-R377 back when I was still in college and had good eyes. It wasn't pretty but it worked!
It just seems like technology has taken a huge leap in the last 15-20 years in not only design but in manufacturing as well. Back in the 50s as you state, the techs of the day probably did complain about circuit boards.........but circuit boards didn't change a whole heck of a lot since then. The biggest leap multi layers and surface mount. I'm sorry but there are things that machines can install that I am pretty sure I don't have enough magnification or a steady enough hand to de-solder or re-solder. Not to mention I don't have the time or the money to experiment with such things. I did at one point build a crude hot air rework "gun" which did sort of work but I'm sure nothing can match a professional unit. Point being that you won't find many (or any) shops repairing much at component level anymore..........and I really can't blame 'em.
I've never used Chip-quik but it seems like it might be handy. The other problem I have with a lot of modern stuff is I can't find data sheets for a lot of components but I'm sure a lot of that is knowing where to look.
Now, having said all that, I am really glad to have found someone who is able to and willing to spend the time to fix modern stuff, it gives me inspiration to continue to try!
Good work! I think I'm going to like hanging around here.
Oh, and if you are good with tubes, I have an old console radio that I got for decoration in my living room but I would like to see if I can make it work someday. I think it's all there.
Cheers!

[kc8adu]

Re: RCA CRT TV Flyback?

You may be right about that but there used to be TV/stereo shops all over and now you have to take or send anything to a big city to get it worked on. There are still some guys (myself included to some degree) who still do a bit of it but it seems that many of us have not kept up with any of the newer technologies. I realize it is possible to do surface mount without all the hot air tools etc. as I have done some, the first being a processor IC for the display on my old Technics SA-R377 back when I was still in college and had good eyes. It wasn't pretty but it worked!
It just seems like technology has taken a huge leap in the last 15-20 years in not only design but in manufacturing as well. Back in the 50s as you state, the techs of the day probably did complain about circuit boards.........but circuit boards didn't change a whole heck of a lot since then. The biggest leap multi layers and surface mount. I'm sorry but there are things that machines can install that I am pretty sure I don't have enough magnification or a steady enough hand to de-solder or re-solder. Not to mention I don't have the time or the money to experiment with such things. I did at one point build a crude hot air rework "gun" which did sort of work but I'm sure nothing can match a professional unit. Point being that you won't find many (or any) shops repairing much at component level anymore..........and I really can't blame 'em.
I've never used Chip-quik but it seems like it might be handy. The other problem I have with a lot of modern stuff is I can't find data sheets for a lot of components but I'm sure a lot of that is knowing where to look.
Now, having said all that, I am really glad to have found someone who is able to and willing to spend the time to fix modern stuff, it gives me inspiration to continue to try!
Good work! I think I'm going to like hanging around here.
Oh, and if you are good with tubes, I have an old console radio that I got for decoration in my living room but I would like to see if I can make it work someday. I think it's all there.
Cheers!

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the badcaps forums of antique radios.