Rca 21-t639
 

Hey guys. I recently found this lovely RCA 21-T639 outside of a house, a few minutes before the garbage truck came and took it away forever.

The lady who threw it out (not literally thrown, by its condition) said that it came with her house and had been in a garage area for years, she plugged it in and got sound but no picture, and she didn't want it taking up space so she kicked it to the kerb.

I saw it was missing a ballast tube so I dropped one in (after waiting 2 days for it to arrive from ebay), and plugged the TV in (don't yell; i figured if it had already been powered on and got sound, i just might be lucky....). I got sound and a blurry horizontal line. It got very sharp and then I heard that "TV high pitched mosquito noise" go very high, the sound cut off and I saw the Horiz tube (the one with the little cap) arcing purple and dropping sparks down its interior so i immediately unplugged the TV.

*sigh* you can flame me now.

What do you think it would take to restore this old beast to working order? It would look so nice my living room. Is there anyone who does restorations for sets like this?

A ballast?

yeah. i bought a NOS ballast tube and put it in.

i can't find anything about the TV on the net....

A ballast?

Ok, were just a little surprised to hear that it has one. I don't think that was common in an RCA of this vintage. There are some members here who work on sets for others. It would probably help if you posted your location.

Almost certainly it can be fixed. :yes: There are probably some parts in it that could be showstoppers, but odds are it can be fixed.

It's old enough to have paper capacitors, so those should be replaced. Testing the crt would be a good thing to do.

John

Hi:

Your set is from 1956. The RCA 17 inch sets of that era had a ballast tube, I believe, but the 21 inch sets had a standard transformer and 5U4 rectifier tube power supply. What is the chassis number? Should be something like KCS-97.

Steve

I'm from San Antonio, Texas.

I stay at my dorm; the TV is across town. I'll check on it soon and grab the chassis number. Yeah, it has a ballast. The diagram says so. 6AX4 GT, is the tube, i think.

Actually a 6AX4 is a damper tube. I am surprised that the diagram calls it a ballast as a ballast tube is usually a resistance device that is found in a power supply to keep current constant.

Steve

If it was mine I would replace all the paper & electrolytic caps & put in a new horizontal output tube. Chances are very good that it will then work. You could skip some caps and just try the ones in the horizontal/HV circuit but my experience is that those caps you leave will come back to haunt you. The vertical section in particular will not work right with marginal or bad capacitors. As Blue Lateral said, having the crt tested would be a good idea. If it was very weak or bad you would then have to face locating a replacement. Not the end of the world but it might make this not worth the effort. Maybe you can borrow a tester from somebody? It wouldn't have to be a very fancy unit. I'll admit that if I was in your shoes I would get impatient and throw another output tube in there and see what happens, but that is not what you are supposed to do!

the horizontal tube (it has a little "hat" connector with a wire leading into a HV cage) has a metal ring around it, on the chassis. Since it was connected to the HV cage and had that metal attachment to the chassis I didn't want to touch it, even a couple of days later since I dunno what's in the cage (a giant capacitor, with my luck). It's like a metal ring that's bent upward on the sides. I tried prying it up gently with a flat tip screwdriver, but no dice.

also, the picture tube isn't an RCA. it has the 60s Sylvania logo... obviously someone loved this TV enough to retube it. I don't think the tube is weak -or- bad, judging by how bright that horizontal line is. So.. who wants to fix my TV, LOL. I suppose that in order to do a complete and accurate repair I couldn't just ship out the chassis, because you'd have to align the tube and all that. *sigh*. How would you ship an old, heavy beast like mine, anyway?

That bent metal arrangement is there to hold the tube in place, often used on rectifier and horizontal output tubes, especially on sets with a vertical chassis (the chassis is up and down, usually wrapped around the neck of the crt, instead of laying flat on the bottom of the cabinet) this was common around the time your RCA was made. You need to push down on both sides of that spring while pulling the tube out. I know, because those HV cages are tight it can be unnerving to have both hands down in there. You can discharge the HV by shorting the picture tube HV lead to chassis ground. One method is to get a large, straight slot screwdriver and connect its shaft with a jumper wire to the chassis, then stick the tip behind the connector of the crt so that it shorts. You will hear a snap if there is voltage stored there. Leave it there for a few seconds and then do it again. Then it will be safe enough to work in the cage no matter what you touch, provided the set is unplugged!

You wouldn't need to ship the whole set for repairs, you could just send the chassis to someone who could use a test CRT to power it up. Still a pain to ship but doable.

you know, I would be more than glad to ship the chassis out to bring my new (old) friend back to the land of the living. I would love to watch some old movies on the thing. Something tells me if you fed it MTV it would blow a tube in spite.

I've been obsessively researching vintage television. I'm being driven by much the same desire; it's weird but I like to listen to MP3s on my (mid to late 50s) Zenith tube radio, just because I like the rich, liquid, mellow warmth of tube audio. I suppose it's a testament to their design and engineering that they still serve us 50 years later... I bet if I bought a TV at walmart today, with new caps and etc, the RCA would outlive it, even with 50 years under its belt.

Chassis numbers (by the electircal socket):

KCS101
603L5
RBV274

they were stamped one line after the other.

the chassis does indeed look like a PITA to remove. I tried removing the gun connector but it feels reeeally loose so I'm not gonna F it up. How did ya'll get over your fear of ruining things and start fixing these beasties?

I'd bet capacitors would be all you need. If you got light on the screen earlier (even though you lost it), it's likely that the CRT is in good enough shape to give you a picture.

In the first photo... Is that a clock under the control door???

For future reference, don't do what you did again. Purple arcing and dropping sparks inside the horz tube are not cool things to do. :D

Yes, it has a clock under the control door. So. Who wants to fix my TV? :D

Chad Harris is in Texas isn't he? He could do it. Not sure what area he is in, or how far of a drive it would be for you.

oops... His last name is Hauris. He's in Midland.

OK. Does anyone have a SAMS for this set? I want to get it off the front porch and back to life.

If someone here doesn't speak up, you can get one directly from sams technical publishing
http://www.samswebsite.com/cart/cart...o=pf&id=132187

bout 15 bucks plus shipping.

Get yourself a good variable temperature soldering station, a variac, solder vacuum or wick, some 60/40 rosin core solder, and a good work bench to prop the chassis up on while you work.

Get your caps from justradios.com I was recommended to them from members here and have not been disappointed by pricing and service.

Personally, I would just talk to Chad Hauris. He's worth the drive to get this set done quickly. He can help you out. You can tackle this one, but if this is your first and you want it done the right way the first time, take it to a pro :yes:

oops :P i feel silly now.

Which one should I buy, 639U or 639? Mine is the "Super" with Teletimer

I just happen to have the factory service manual for your set. Trade you a copy for your set?:D PM me with your address and I will send you a copy.


polaraman

http://www.radioshack.com/product/in...entPage=search

soldering station?

http://www.radioshack.com/search/ind...rosin%20solder

solder

http://www.radioshack.com/product/in...entPage=search

solder vac



is that stuff OK? and $250 for a variac? HA!

pass on that soldering station. Check out MCM electronics or parts express and get a good Weller temperature controlled solder station. They last forever and are well worth the money.

http://www.partsexpress.com/pe/pshow...36&rak=372-120

this one?


and polaraman, which one would list the parts that I need? the service manual or the SAMS? I've seen some stuff in the service manuals and it all seems kinda scary. How many caps does the average old TV like this have, that need to be replaced?

that would be ok for most projects. However you may want something in the 50-80 watt range for the big filter caps, or grounding parts of the chassis that easily absorb heat.

Average caps can be from 20-50 paper depending on the TV.

Weller WTCPT. These things are the bomb. :yes:

http://www.cooperhandtools.com/_cach...1c49a80a3f.jpg

I think it used to be called WTCPS, if you see used ones on Ebay or whatever.

John

Yep. That's what the techs at work have. Weller. Don't even fool w/anything else.

...

hmm... which will show me the parts i will need to recap the set, service diagram or sams?

Bump

You need a Sams folder! It lists and picture points every component. The lists show component values, replacement part#s, and some cross reference. I now find them to be very necessary and covienient for making parts order lists.

sams is on its way :shifty:

*kickbump*

Okay, this TV has been sitting on my porch for almost a year. I really feel bad about it and want to get it running again. Last time it was powered up I got a horizontal line.

I'm planning on removing the chassis tomorrow. Does anyone have a service manual?

Hi Fuji,

I don't think I have a Sams for it but I do have a Beitmans book with a schematic.
I can scan it and upload it for you.
Give me a day or so.

It looks like it uses PC boards so it should be fairly easy to replace capacitors.

Eric

I should have the fulls RCA Victor service manual I will look and update this when I run into them . the RCA s that were made in that time seemed to have the same chassis an several sets I don't have a scanner yet and wont have for 2 months , maybe earlier . However , if you paid for the shipping and photocopys , I will gladlly send you a set , they are full RCA original publications , and the service info is around 5 ? pages long , more or less .
5 bucks will probably all that . the schematics that I have are for the sets made in Camden NJ. USA.

Ill go through my files and keep in touch . :banana:

I like that banana so I felt the need to stick it there .

Murray.

I just feel so horrible about the TV sitting outside... I hadn't been around the site for awhile, but now that I'm back I'm fired up about trying my damndest to get this thing displaying a picture, even if it IS only for a few seconds.

One thing i noticed is that the black connector on the CRT seems to be a bit loose on the glass.. would it be advisable to spray WD40 on the pins and use a plastic tool to gently pry the cable away from it? What I want to do is disconnect the chassis from tuner, CRT, and put it on a bench; then on Thursday when the paycheck arrives I'll get a decent soldering station. It's just the capacitor values that'll give me a bit of trouble, i'll be honest i've never undertaken a project like this before but i'm willing to try.

i take it most of them would be orange drops? what else would i need?


http://i28.photobucket.com/albums/c2...er/chassis.jpg (There are 2 more bolts on the other side. Is that all that's holding the chassis down?)

http://i28.photobucket.com/albums/c2...tier/clock.jpg ("Television Movement")

http://i28.photobucket.com/albums/c2.../brokepots.jpg (Will I have to replace these pots as well?)

http://i28.photobucket.com/albums/c2.../pencilbox.jpg (Open pencilbox)

http://i28.photobucket.com/albums/c2...r/oddsends.jpg (WTF are all those springs?)

http://i28.photobucket.com/albums/c2...thistoowtf.jpg (Do I have to remove this TOO?)

http://i28.photobucket.com/albums/c2...tunerwires.jpg (wires from the tuner)

http://i28.photobucket.com/albums/c2...thisgetter.jpg (is this getter? the tube lights up though!)

http://i28.photobucket.com/albums/c2.../yokewires.jpg (these are the ones that ctrl the yoke, right? how do I disconnect the slender white one?)

Fujifronier , I dont have the exact schematic book for your set , but I got one that might work , what I need to know is what tubes your set has on the tube list then I will compare this with the ones that I have some of the RCA's had the same parts but when next years model came out they put the parts in a different chassis the one's that I have that are similar are for the

KCS 108 chassis
model 21 vf 8695 from 1957

Does anyone Know if this will help fujifrontier ,
or are they different ? it's too bad the tv wasn't a 1951-54 models because I have a stack of them , perhaps for every rca tv made in those years .

You can possibly get the set going without the schematics , the one page that you have will do it , the recap. is not bad to do , the wax papers are easy . I have done it with no schematics and the easiest way is to nip off on lead at a time on the cap and solder the new one in . A friend of mine that has been doing radios for maybe 40 years told me this one , Cut the wire off the old cap and make a little hook with a pair of needle nose pliers and trim the new cap and do the same and then you can hook the two looks together and pinch them with the needle nose pliers and solder them together . then do the same on the other side . I've used this method over and over for years and had exellent results .

Make notes of everything you take apart and , What I do is take the camcorder and film anything I might question in the future when I assemble it . Also if there is no tube list take a pencil and write the tube numbers beside the sockets . once you pull the chassis it will look alot more simple , just do a couple a day , thats the easy way . I would say there were 30 in the set . best of luck on it .

http://i28.photobucket.com/albums/c2...er/chassis.jpg (There are 2 more bolts on the other side. Is that all that's holding the chassis down?)
Probably.

http://i28.photobucket.com/albums/c2...tier/clock.jpg ("Television Movement")

http://i28.photobucket.com/albums/c2.../brokepots.jpg (Will I have to replace these pots as well?)

Those aren't broken, they are recessed because they are not usually adjusted by the consumer.

http://i28.photobucket.com/albums/c2.../pencilbox.jpg (Open pencilbox)

http://i28.photobucket.com/albums/c2...r/oddsends.jpg (WTF are all those springs?)

Don't know, maybe ground springs for the CRT or else they hold some of the wires up?

http://i28.photobucket.com/albums/c2...thistoowtf.jpg (Do I have to remove this TOO?)

Not if the wires unplug from the chassis.



http://i28.photobucket.com/albums/c2...thisgetter.jpg (is this getter? the tube lights up though!)

That is the Ion trap, make a note of how it's positioned, (this picture will do nicely) it has to be adjusted correctly or nothing will appear on the screen.

http://i28.photobucket.com/albums/c2.../yokewires.jpg (these are the ones that ctrl the yoke, right? how do I disconnect the slender white one?)

Are you talking about the white one going to the side of the tube?
Use care here, that's the high voltage lead, the tube can store a charge too and shock you, not fatal but enough to make you recoil and injure yourself or break something. Discharge it to the black coating on the CRT before touching it, do it several times to make sure, then just push it sideways and unhook the clips from the hole in the tube. Do not force it!

Your comments have all been very helpful, i really do appreciate the tip about the capacitor leads. Re: the schematic.... I can't find it. I think mum may have thrown it out. *SIGH* I would like to try that as opposed to unsoldering each and every lead; at least this way i'll have some extra room. I didn't have the time today to start pulling the chassis, but while taking my pictures, from what i could see through the grille underneath I noticed that it does indeed appear to use a PC board type.

To discharge the CRT, do I just touch a screwdriver to the leads and short out both contacts, or could i just be very careful and wear a pair of thick gloves while removing it?

I think i'm going to practice recapping an old philco radio that's been sitting around here... if I can get her squawking again then I'll feel fully confident I can do the same with the RCA.... it's just a bunch more caps.

From the lurking I've been doing lately i think all this old gal needs is a recap, and some furniture polish and I'll be watching I Love Lucy before i know it :)

Not to drag us too far off topic - but what would be the best thing to use on semi weathered wood like this, to restore some of the original tone and luster? any place to get similar replacement grillecloth?

Fugifrontier , How are you doing with the chassis , did you get it out allright ?

No. I haven't gotten it out. I plan to take it out when I've got the Philco i posted about in the "Antique Radio" thread singing again, unless you want me to send it to you to work on :)

At least then we'll have established I know what I'm doing and am capable of recapping the RCA