1960s Sylvania Color TV: My first all tube color TV

[zeno]

The resistors looked "different". IIRC they turned color & got a bubbly
coating on them. Lift one end & retest them.
Same with transistors not in sockets. Lift 2 out of 3 leads & test with
DVM on diode test. We had a few transistor checkers & they collected dust.
Only one tech used them & he was playing engineer & wasting time.
Bottom line is parts IN circuit very often read bad.

73 Zeno
LFOD !

[Electronic M]

Originally Posted by old_coot88

Do you happen to remember the + source those two resistors are fed from? Seems like it as a lot higher than 24V, but I could be wrong. Also I could be wrong on the 27K value, but that's the figure that sticks in mind. A schematic would sure be handy.

Unfortunately no, but 98% chance I have the schematic. I'm hoping to have bench time this weekend, maybe I can dig it up while I'm down there.

[vortalexfan]

I saw that my Sylvania TV is in Sam's 1045-2 which I don't have a physical copy of and I try to avoid buying the PDF copies from them unless I have no choice in the matter because I think its ridiculous to charge $22 for a PDF reproduction of an original service manual that may or may not be of that great of quality compared to the original paper document, and feebay is hit or miss on having original Sam's Photofacts for sale, and some times they want just as much on feebay for an original Paper copy as Sam's does for a PDF reproduction. Which is why if someone on here has an original paper copy that they can scan and upload I prefer to go that route rather than having to pay $22 for a photocopy of an original Sam's, or if I can hold out for someone locally that might have a bunch of old sam's folders that they are liquidating from their collection for a decent price, like what Shango did.

[vortalexfan]

Well, I did suprisingly enough manage to find an original hard copy of Sam's folder #1045 (the whole folder, not just one of the sections out of the folder) for $9 plus shipping.

But I had to search a little bit because there weren't many listings for individual Sam's folders, they were mostly just listing the compilation books or selling a set of Photofact Folders as a lot (with one such listing being listed for $800 for a set of 50 complete Photofact folders that were in no particular order) with only 2 listings that were selling individual folders out of a lot of 50 or 100 Sam's Folders, that I'm assuming came from an old repair shop or an old Library collection.
The one listing that was selling individual folders out of a full lot of Sam's folders had Folder 1045 but it was already sold, and the second listing had 2 Sam's 1045 folders and one had already sold and I had just bought the last one out of that lot.

So it seems that these Sam's folders are getting harder to come by unfortunately.

[dieseljeep]

Originally Posted by vortalexfan

Greetings everyone, I will be picking up tomorrow locally a mid to late 1960s Sylvania Color TV that appears to be from what I can see of the pictures an all tube Color TV or perhaps a hybrid (I'm not sure becuse the pictures I saw of the inside of the unit were kind of limited to a small area of the main chassis where I saw at least two or three tubes in the picture and the convergence board and the picture tube besides a front view and a back view of the unit with the cover on the back.

The person who listed it on facebook marketplace said her husband picked it up at a garage sale several years back with the intention to fix it up but he lost interest in it, she said that when he powered it up it produced sound but no picture which I'm wondering if either the HV Rectifier is dead or maybe they were too impatient to wait for it to produce a picture, especially if it didn't come equipped with the "instant on" feature. One thing I did notice about the TV from the pictures of the inside of the set that I could see, is that it looks to be a low hours set because it has very little dust built up on the picture tube and on the chassis, and the TV appears to have the original Sylvania picture tube in it yet and the cabinet looks darn near mint.

what do you guys think, will this be a good TV when fixed up and what kinds of things should I look out for when trying to restore this set?

Thanks for your help.

See pictures below.

How did the Masonite back get all broken up.
It must be a curbside pickup, that someone tried to get to the yoke!

[vortalexfan]

Originally Posted by dieseljeep

How did the Masonite back get all broken up.
It must be a curbside pickup, that someone tried to get to the yoke!

I don't know how the back cover got broken, I just know that the person I got it from on facebook market place said that her husband picked it up from a garage sale 10+ years ago and intended to fix it up but had some health problems that got in the way of that endevor.

[vortalexfan]

Originally Posted by old_coot88

Do you happen to remember the + source those two resistors are fed from? Seems like it as a lot higher than 24V, but I could be wrong. Also I could be wrong on the 27K value, but that's the figure that sticks in mind. A schematic would sure be handy.

According to the circuit Board the + Voltage feeding those resistors is +340 volts.

According to the resistor color coding on the 2 2W carbon comp resistors you're referring to are supposed to be 68k Ohm resistors and then there are 3 green wirewound resistors on the same board that are 27k Ohm 3W power resistors which all measure within spec yet, but the 2 2W Carbon Comp Resistors which are supposed to be 68k Ohms are measuring only 16k Ohms or so, so it sounds like those carbon comp resistors need to go bye-bye, because they are WAAAAAYYYY out of tolerance.

Probably what I'll do to replace those 2W 68k Ohm resistors is cut them off on either side of the resistor element casing and then solder a new one onto what's left of the wire connectors above the board so that way I don't have to worry about risking damaging the circuit traces underneath the board, since they left about a 1/4" of wire lead above the board surface.

[old_coot88]

IMHO you'd be better off waitin for a Sams to double-verify those resistors' value. Code stripes can change color from excessive heat over long duration. Gotta wonder if the two transistors might still be good though.

[vortalexfan]

Originally Posted by old_coot88

IMHO you'd be better off waitin for a Sams to double-verify those resistors' value. Code stripes can change color from excessive heat over long duration. Gotta wonder if the two transistors might still be good though.

I have a Sam's on order from feebay, that is an original full 1045 Folder that I got for $13, it supposed to be here sometime this week.

When I get that folder I'll take a look at the manual for the TV and double check the resistor values.

[vortalexfan]

I got the manual for my TV in the mail today and I just confirmed that the 2 2W Carbon Comp resistors in the TV were indeed 68k Ohm 2 watt resistors and what I was measuring on them using my VTVM was about 16k Ohms which is indeed way low.

And I believe that VTVMs can be used to measure resistors in circuit regardless of there being a parallel load on them or not because the VTVM applies a voltage to the resistor when measuring it that makes it read like the resistor is out of circuit, at least that's my understanding of how VTVMs work, compared to DMMs.

[old_tv_nut]

Originally Posted by vortalexfan

....And I believe that VTVMs can be used to measure resistors in circuit regardless of there being a parallel load on them or not because the VTVM applies a voltage to the resistor when measuring it that makes it read like the resistor is out of circuit, at least that's my understanding of how VTVMs work, compared to DMMs.

That is not correct for an type of resistance meter. When a resistor is still in the circuit, other conducting paths will be measured in parallel with the resistor, which will make it read low. How much lower depends on what is in parallel in the circuit. This is a property of the circuit, not the meter.

[vortalexfan]

Originally Posted by old_tv_nut

That is not correct for an type of resistance meter. When a resistor is still in the circuit, other conducting paths will be measured in parallel with the resistor, which will make it read low. How much lower depends on what is in parallel in the circuit. This is a property of the circuit, not the meter.

OK, well I guess I won't trust what my VTVM's manual says, because the manual for my VTVM said that it was supposed to be able to read resistors in circuit without the need to clip them out, unless I misunderstood what it was saying?

Anyways regardless the resistors should be easy to clip out of circuit because they do stick up above the board about a 1/4" so which means that if those resistors are actually fine then I can just solder the resistors back onto the leads that were clipped.

[Electronic M]

Originally Posted by vortalexfan

OK, well I guess I won't trust what my VTVM's manual says, because the manual for my VTVM said that it was supposed to be able to read resistors in circuit without the need to clip them out, unless I misunderstood what it was saying?

Anyways regardless the resistors should be easy to clip out of circuit because they do stick up above the board about a 1/4" so which means that if those resistors are actually fine then I can just solder the resistors back onto the leads that were clipped.

Two things:
One while you can measure resistors in circuit with any resistance meter the reading in circuit is never guaranteed to be the actual resistance of the resistor due to parallel paths. No meter can eliminate parallel paths...If it claims to, it's lying. When measuring resistor in circuit if the value is exactly as rated or higher it's probably accurate, if it's lower you have to unhook one lead.

Two it's really better to pull the chassis and solder on the board than clip and tack it back together, both from a neatness standpoint and from a on thicker leads to get a good joint you can end up melting the old board joint causing the lead to fall through the board or a cold solder joint on the board to develop standpoint.

[vortalexfan]

Originally Posted by Electronic M

Two things:
One while you can measure resistors in circuit with any resistance meter the reading in circuit is never guaranteed to be the actual resistance of the resistor due to parallel paths. No meter can eliminate parallel paths...If it claims to, it's lying. When measuring resistor in circuit if the value is exactly as rated or higher it's probably accurate, if it's lower you have to unhook one lead.

Two it's really better to pull the chassis and solder on the board than clip and tack it back together, both from a neatness standpoint and from a on thicker leads to get a good joint you can end up melting the old board joint causing the lead to fall through the board or a cold solder joint on the board to develop standpoint.

OK, well anyways with one of the legs of the resistors removed from the circuit, my VTVM (which for some reason that's all I could find, because I somehow misplaced my DMM) the resistors read 75K Ohm which is higher than the rated 68K Ohms, and those resistors are 10% tolerance so I don't know if they are measuring within tolerance or not but it still sounds like they may need to go either way.

I was reading/following another member's thread where he was repairing a Color TV of a similar vintage to mine (the one where he was working on a late 1960s Motorola Color TV that had issues with the color not wanting to lock in correctly) and there were some suggestions about using some 2%-5% tolerance resistors in the IF and Chroma sections of the TV to get it to work better.
I wonder if in my TVs case that might be something worth looking into to get the TV functionality more stable, because my TV is essentially exibiting those same issues as that Motorola TV in the aforementioned thread, where the picture and color are not stable.

[vortalexfan]

UPDATE: I was able to locate my DMM and I was able to confirm tha those resistors were indeed around 75K ohms so like I said I'm guessing that is way above the 10% tolerance the resistors are rated for so I'll need to replace those for sure.

So according to my calculations the resistors are just barely outside of the 10% tolerance range, 74,800 Ohms and under is within the 10% tolerance range of the 68K Ohm resistors and the resistors were measuring 75,300 Ohms...

Which is probably the reason why those resistors haven't cooked themselves yet and also probably the reason why the transistors may not of fried yet, but are still affecting the picture quality, but also I haven't ran the TV for more than a few minutes at a time to do some troubleshooting and shutting it off in between.