Picked up the Sylvania yesterday, but didn't get it into the house until this afternoon. Nephew was helping and I noticed all 6 knobs at the bottom had fallen off at the same time. When I opened 'er up, I found out why--the chassis was bumping around inside the cabinet! I think one more good jolt and the picture tube would have been a goner.
The picture tube, by the way, must have been replaced at some point because it's an RCA Perma-Chrome Hi Lite.
The chassis is DO211, which makes the model number 25LC105, according to the SAMS.
This set has some weirdass tube sockets. They're more like just a bunch of little connectors on the PCB rather than regular Bakelite sockets. There are some regular sockets, too.
Okay, so I fired her up and the pictures tell the story. The picture actually looks focused to me, if smallish and green. The pic looks B/W, but it's really green. The first time I turned it on, the picture was more orange. The color and tint knobs don't seem to do a dang thing. I had to fiddle with the HHold knob a little to get a picture.
In poking around a little, I noticed that some of the tubes in the weird sockets were loose. This may be what the service guy meant when he said the sockets were worn out. Is there a good way to tighten these up?
Other problems are that the channel numbers don't move in the window, it needs a light for the UHF tuner, a brace inside neets to be reattached, and there's about 40 years worth of dust I have to vacuum out.
Once I get it cleaned up, I was thinking of messing with the height control to see what that does, if anything. It also looks like I'll need to straighten out the yoke, but it might be just my eyes.
Any ideas what to do next? Is the single-colorness going to be a problem? It actually looks like my Heathkit does, but then the blue gun kicks in and I get full color. Haven't had this set on long enough to see if there's any change once it gets good and warmed-up.
Forward!
veg

The focus looks okay from here. I'd say by "won't focus" maybe they really meant it just wouldn't tune in clear. I'll wait until you've done more tube-jiggling & preliminary work before making any guesses.

Focus can mean anything from fine tuning to convergence to 'regular' people.

The tube sockets that look weird are where all of the plastic has worn away due to heat...for a reliable connection you need to replace the socket using a new good socket with bus wire soldered to each pin to run back to a good point on each trace (the board may be burned right at the connection point the socket).

You can see in the picture of the chassis that one of the tubes is crooked...you won't get a reliable connection with the worn out sockets.

Okay, I spent some time last night cleaning and adjusting and stuff, and here's what I came up with (sorry no pics yet. With luck, I'll be able to take one tonight):

Got a nice, clear, well-focused green picture after twiddling the fine tuning. Messed with the height, v. centering and v. linearity controls and have a picture that fills the screen. People's heads seem to be the right shape :D so I guess I got the linearity right. Straightened up the yoke, but I don't think I tightened it up again as it's a little off. Or maybe I'm a little off.

Did the gray scale adjustment in hopes of restoring some color. I got nice bright green and blue lines but no red, no matter which bias setting I used. Cleaned the drive controls for good measure but no change. Set had been on for maybe 30 minutes at this point. Snapped it out of service mode and was presented with a really nice BW picture!

This lack-of-red thing has me concerned. If there were really NO red, wouldn't the picture have a blue or green cast to it? It's really nice black and white. The convergence is off at the edges (natch) and I can definitely see some red up there. Does that mean anything? Should I test the tube and maybe give it one of those jolts that "restore" it? Anyone got a tube tester I can borrow?

The color and tint controls still have no effect on the picture, so I'm guessing they're involved in this somehow.

Color or no, I'm really pleased at how much progress has been made with just some minor tweaking. Picture to come!

veg

The drive controls adjust the amount of the video signal coming from the B&W video output tube to each of the cathodes. These are not adjusted during the service line procedure as there is no video signal at the cathodes at that time.

When you set the switch to service you adjust the SCREEN controls for just-visible equally balanced red green and blue lines. Careful...there can be 1000 volts at the screen controls.

Thanks for the heads up about those 1000 volts. I had no idea!

You're absolutely right--it was the SCREEN controls I used for the grayscale setup. Still didn't get any red though. Tweaked up the blue and green drive knobs to get a nice BW pic with no color in it.

One of these days I'll get the terminology down. In the meantime, can't I just call everything the Frammis Meter and the Gronkulator?

veg

Check the tubes that are marked R-Y, B-Y, and G-Y. If the Red Y is out, this can cause your problems. Most sets had all 3 functions in one tube, Magnavox did, fer sure. My RCA's have 2 6CG7's that do all 3 and a cutoff function.

Best of luck. Dont give up on it. You should find your problem pretty fast.

Be sure to check the Glonkkulation supressor and the Horizontal Disconsimulator. Sylvania invented that one! :thmbsp:

The Glonkkulation supressor! Man, I completely forgot about that! :D

I'll drag out my cross-channel supressor compressor tonight and check it out.

Got out the ol' camera and fired up the set tonight so I could show the progress. I read something about maybe the color killer being misadjusted so I went around and twiddled with it, but didn't seem to do diddly.
Then, as I had heard others do, I started tapping tubes. Okay, now that made some difference! There's some color now, but not in the right places at the right time. I'm going to take a stab and guess that the color sync is out of whack?
Anyway, enjoy the pix!

veg

Replace those bad tube sockets and that may go a long way to getting the color back in sync. Also check for bad solder joints on the circuit board.
Good Luck,
Bill R

Veg, Can I have it after it is fixed? :D


polaraman

Veg, Can I have it after it is fixed? :D


polaraman


Nope. You turned this down once already. "The time to take the hotcakes is when they're passed!" :D

veg, who's kind of amazed, actually

I did a little online shopping for replacement tube sockets. Since the original ones were apparently burned to a crisp, I guess the new ones should be ceramic? Or does it really matter?
I also came across something called a "socket saver". What is this, and do I need one? It was about 8 bucks, as compared to like a buck and change for the sockets themselves.

I think any sockets that would solder to your pc board will be plastic like the originals probably were.

Are your circuit boards burned/crumbling too or are only the sockets bad?

John

Socket saver...hmmm. I've never messed with one of them, that might be an easier way to go? Maybe someone else knows. I think I have one in my box of sockets, will have to check it out. That color is awful close. Could just be a tube thats kinda on the edge. I can tell you that changing the sockets won't be a walk in the park.

So Polaraman wants the Sylvania, Veg wants Allen the DuMont back, meanwhile there sits Anthony the Heathkit looking for a home...'round & 'round they go....

I am proud of you, Veg, you're doing well!

Oddly, the circuit boards look fine. Really great. So good, in fact, that I assumed they were just weirdass tube sockets. No burny marks, no darkening of the PC board, nothin'. I figured Sylvania just cheaped out.

veg

Can you post a pic of one?

John

I am proud of you, Veg, you're doing well!

Let me change your mind about that!

Not willing to leave well enough alone, I pulled a 6JU6 out of Anthony and tried plugging it into one of the funky sockets in Woody (henceforth, the Sylvania's official name.) Naturally, the fit was less than ideal, so I was wiggling it around a little to see what would happen. Not much as it turns out.

Sorta.

While jiggling the tube, it came right off in my hand. No change in the picture, oddly. So there I was, holding the tube when there was a small puff of smoke. It came from between the chroma board and the bigass transformer that's to the left of it. I'm pretty sure it didn't come from the transformer itself. Nothing seemed unduly hot. And it was a small puff. Didn't look like anything was smoldering or anything.

There's a red circle on the picture over where the smoke came from. Whoa! Kindly pardon that syntax!

I'm not sure what those three little spiky things are by C145. Spark gap? The puff might have come from there. There's still a significant amount of dust down there. C145 was nice and cool. The green resistors next to it were hot, but I think they always were.

Oh, and now there's no picture at all. I'm not even sure if anything on the chroma board still lights up. At that point, I put everything down, turned it off, and walked away before I made it even worse. Smart boy, sometimes. Usually too late, though.

All righty. Since I have to pull the chassis anyway to replace the tube sockets, could someone remind me of the easy way to discharge that anode thingie without killing myself? Never pulled a chassis before, but the instructions in the SAMS look pretty easy. And it's not attached to anything right now anyway.

Got my new camera last night, so I'll try to take a picture of the busted-up tube sockets.

Yeah, when I started making progress the very first night, I figured I was going to do something to use up my good karma...

veg

The way I discharge the anode is to take a meter probe lead and connect the end that would plug into the meter to an alligator clip lead. Connect the clip lead to the CRT grounding spring or degaussing shield if there is a ground connection point there. Then stick the meter probe under the anode cover till a spark is heard. You can then push the anode cap connector to one side to release the spring clip.

Also...you can use a little screwdriver firmly connected to an alligator clip lead and do the same way. Just be sure the tool has a firm ground connection to the crt degaussing shield or grounding spring and an insulated handle. I prefer the meter lead method.

And you should re-discharge the CRT before you re-connect the anode lead as the charge can reacuumulate after the first discharge.

The points near the cap that you are refering to appear to be connection points that wires would connect to underneath the board.

How much functionality do you have with the set now? Is there any sound? Do you get lines with the service switch turned to service?
Do any of the tubes light?

Just a few more questions.

Chad, thanks for the good instructions. Does the wire on the probe and the alligator-clip wire have to be a certain gauge? My meter is like a 10 buck digital thing, and I have a bunch of alligator-clip jumper wires that I got at Radio Shack. They don't seem particularly hefty to me.

Will the CRT grounding spring be obvious to a simpleton like me? There's apparently a ground wire that needs to be disconnected before I can remove the chassis, but the SAMS doesn't say where 'tis.

Okay. Assuming I get the chassis out without killing myself (about 50/50, I think), how do I re-discharge the pic tube when I put everything back in? I couldn't just plug the anode thingie back in the hole?

As for functionality, I still have sound. The picture tube is dark; the front, at least. Don't remember checking to see if the filaments were lit. I don't think any of the tubes on the chroma board were lit, but others were. This happened last night, and the mind is going. There were definitely tubes lit on the sound and deflection boards. After that initial puff of smoke, no more and no more burny smells.

I don't know if I'd get anything with the switch in service mode. As I say, when I blew it up, I turned it off and walked away...

Is it really going to be a pain to put in new tube sockets? I was thinking with the chassis out, it'd be a simple desolder-pull/replace-resolder. 'Course I've never done this before, so what do I know? I think there are three sockets that need to be replaced.

Oh, and just for good measure, I looked at the flyback and it's clean enough to eat off of. I know these cause a lot of trouble. I also felt the cans with the electrolytics in 'em and they were nice and cool.

veg

Check for any place on the CRT degaussing shield that is bare metal...if you can't find anything on the CRT shield or you can't see the spring, check for any grounding wire or strap that runs from the CRT to the chassis. You probably could connect the alligator clip lead to the chassis at the HV cage if the chassis is still bolted down and nothing is disconnected. When you remove the chassis you should see the strap connecting the CRT ground to the chassis.

To re-discharge before reconnecting the anode lead you just connect your alligator clip lead and probe to whatever grounding device connected the CRT to the chassis or the CRT degaussing shield if there is bare metal on it. Just stick your probe into the anode connector and you should get another spark. Make sure you do this or you could get shocked from the charge that somehow builds back up in the CRT.

You don't have to have terribly high gauge wire to discharge, just make sure the probe handle you are using is well insulated.

The way I have replaced sockets is to take a brand new ceramic or high quality bakelite chassis mount socket and solder about 6" of bare buss wire to each pin. Remove the old pins of the old socket from the board by using a desoldering braid to wick away the solder. You will then have 7 or 9 holes on the board and you can stick in the corresponding wires from the new socket. Solder the wires to the board under the socket and then run the wires along each circuit board trace back to another connection point on the trace and solder them there too. That will help provide a more stable electrical connection.

The end result will have the tube riding a little bit higher off the circuit board but it is a lot better than using another old socket off a circuit board that may also be brittle. The only problem with the tube being higher is if it should run into something like the yoke...check for clearance. If the board appears in really good shape you may be able to get away with using a new PC mount socket but I would not recommend recycling an old one.

You may have shorted out the filament leads on the chroma board and burned a trace open on the chroma circuit board for the filaments...trace the filament leads from a tube back to where the wires for filament power enter the board and check the circuit out.

Oh boy! Gonna have me some fun tonight. If yall don't hear from me soon...

Okay, so when I go shopping for new tube sockets: are all tubes with a given number of pins the same size? Should I take the tubes with me to the store?

I thought the tubes had 8 pins, but all the sockets I saw were octals, and they didn't look right. Maybe the tubes have 9 pins. Or seven. The sizes are mostly 6Gsomething.

veg

The tubes on the circuit board should be seven or nine pin miniature...the only octal tubes in this set are probably the 6BK4 and 3A3. Just check the pins on the tubes pulled from the suspect sockets.
The other types of tube sockets used in the set will be 9-pin Novar (large nine pin base like a damper or horizontal output tube or certain vertical oscillator/ output tubes) and a 12 pin Compactron base (certain other large tubes and multi-function tubes).

I found one socket saver in my pile, its for a compactron base. I don't fully understand how it works but I guess you just plug it in the socket & it has a threaded shaft that goes through the hole in the middle which you would thread a nut on from underneath. (I guess) But I don't know how beneficial it would be. Unless the pins on the saver are maybe a little bigger guage for a tighter fit? I think if you use Chad's method with a good new socket you should be fine. Just take your time so as to find the right traces. I've only had to replace one socket on a board myself & I think using this method would be easier than soldering it back in like I did.

My method for discharging the crt is to use a big screwdriver (so that I don't have to get too close to the "action"!) & clip a wire to the shaft, the other end to ground. In this case, with the chassis loose, I would use that metal shell. And before you hook back up just do it again. If you're not touching anything but plastic you'll be fine.

I'm thinking that the socket savers are mainly for tube testers where you are plugging in and out a lot of tubes...if you put the socket saver in the tube tester's sockets when the tester is new, all the plugging/unplugging wear gets taken out on the "saver" and it can be discarded and replaced when it gets worn out, rather than having the tester's socket get worn.

Well!

I followed all the suggestions last night about draining the HV from the anode socket. Clipped the wire to ground, used a test probe and poked it under the suction cup thingie. No snap. No crackle. No pop.

Huh.

Tried clipping the wire to other grounds and still nothing. Oh well, I figured, the juice already leaked out. So I pulled the chassis.

And I'm still here to tell the tale. Can you imagine?

Here's a pic of the chassis out, and another one of a couple of sockets I need to replace. My locak place didn't have them so I had to order 'em online. Hopefully, they'll come this week.

Progress!

veg

Still waiting on the new tube sockets, so not a whole lot of progress has been made.

I took the chassis outside and gave it a good dusting. Looks a whole lot better. Not clean enough to eat off of, but better. :D

While I was at it, I pulled the tuner, too. Fixed the channel number selector and replaced the bulb for the UHF tuner. While it's out, should I go ahead and spray some cleaner on the contacts? I'll really only be using it on channel 3 and tuning with the VCR.

This set seems to be from somewhere between '65 and '67. There is, I think, one paper cap in it. I'll replace it, but isn't that kind of late for them to be using paper caps?

Also, the CRT is really dusty. It's not tobacco-smoky, but the dust clings pretty well. What should I use to clean it? I hesitate to wipe it down with a wet cloth, 'cause I don't want to ruin the aquadag (?). Would dusting it with a Swiffer and not actually cleaning it be okay?

Man, hope those sockets come soon! I looked underneath and on top where that puff of smoke seemed to come from and can't see anything fried. Indeed, I can't see anything that looks out of the ordinary. Any ideas what would cause that?

veg

I think if ever needed to change tube sockets on my tvs due to heat damage--, would use ceramic sockets. Good for handling/insulating PCBs from heat caused by tubes that run hot. Would be upgrade for reliability. That tv is awesome Veg!! More pics please!!!! What does cabinet look like????

:)

Well! Could have knocked me over with a feather, as they say.

After checking all my new solder joints (which never look nice and shiny) and double checking all the tubes I put back in (I had one in the wrong place), I reinstalled the chassis and decided it was time to fire up Woody.

No smoke this time!

There are still a couple little problems, not bad: I need to touch up the convergence. Guess I'll have to get one of those new DVDs from ETF. The cabinet could use a little work on the top, but it's not too bad. And I need to find one more knob. That's the third picture. Anyone got one?

The color doesn't seem to sync really well unless I change the channel from 3 to 2 and then back again.

In summary, this is what I did to get Woody back on line again:

Clean chassis of dust.
Replace 4 tube sockets.
Replace light in tuner.
Reattach channel numbers on VHF tuner.
Probably some other stuff I forgot... :D

Anyway, here's a Before and After. Plus a picture of the knob I need. Can't wait to get the convergence fixed--I got the first season of The Doris Day Show, and I think it'll look really good on this set!

Thanks for all your support. Once again, I couldn't have done it without my AK buddies!

Great job, Veg! You can do convergence in a pinch by using the text from your digital cable on-line guide, the credits from a movie when paused, the Home shopping club etc. and turning the color all the way off, but using the pattern DVD will make it more precise. Just make sure the purity is set correctly...you may be able to get away without much adjustment of the 12 dynamic controls if you set up the purity and do the 3 convergence magnets and blue lateral magnet.

Also set up the vertical height and linearity and the pincushioning the best you can to get a straight, well balanced picture as this will help your convergence too.

Just awesome! This is where the real fun is, taking the set in that first picture & tweaking it to pic 2. What an improvement. Knock on wood, I hope Woody remains reliable for a long, long time!

Looking good, Veg! :thmbsp: