1960s Sylvania Color TV Console Issues

[vortalexfan]

Originally Posted by Electronic M

Frequency is usually determined by RC time constants.... Double check that none of your caps are off by a power of 10 (easy mistake to make) then check for off tolerance resistors.

My D-16 behaved similar and one or two of the higher resistance vertical resistors were testing around double their rated value. Also make sure the tubes are healthy and the vertical lytics are new as either can cause vertical shrinkage.

Thanks for the tips, I replaced all of the coupling/Decoupling caps (film/mylar caps) in the vertical section and the vertical deflection is now working as it should.

But now I'm having issues with the color, I have no green at all in the picture, and tons of blue and not much red, I jiggled the service switch a little to check if that was the issue or not, and sure enough it did affect the color quite a bit and I also heard some electrical popping/snapping noises when I did jiggle the service switch. I had tested the picture tube about 2 months ago and the picture tube tested fine yet so could a defective service switch cause a loss of color in the TV or perhaps a defective color demod circuit (bad tubes or transistors?) I think one of the tubes in the Color Demod Circuit is a 6GH8 (which is one of the tubes that is notorious for going bad prematurely.)

[old_tv_nut]

Best to fix the obvious thing first, so fix the intermittent service switch and then see if you get constant bad color.

[vortalexfan]

Originally Posted by old_tv_nut

Best to fix the obvious thing first, so fix the intermittent service switch and then see if you get constant bad color.

Is there a current part number for that switch that cross-references to something currently available at someplace like DigiKey or Mouser? The reason why I'm asking is because when I would "jiggle" the switch it felt like the switch might fall apart in my fingers at any time because it felt really loose in the housing.

[zeno]

The switch can be deleted for now. Then turn the color all the
way DOWN. Fix the set so its as good a B&W set as you can.Then turn it up & deal with any actual color poroblems
Zeno

[vortalexfan]

Originally Posted by zeno

The switch can be deleted for now. Then turn the color all the
way DOWN. Fix the set so its as good a B&W set as you can.Then turn it up & deal with any actual color poroblems
Zeno

OK, will do.

[vortalexfan]

OK, So I have a Question concerning picture tube checkers, I have a B & K Model 465 CRT Tester that was given to me for free more or less by someone locally that I bought a couple of old radios from on Facebook Marketplace, and when I tested the Picture tube on this TV on this CRT Tester the Green and Blue guns tested like brand new yet (the meter was pegged out at the top in the emissions test) but then the red gun didn't budge the needle at all (it was showing no cutoff and the red gun was registering all the way at the bottom of the meter) This CRT Tester I have uses a switch with 3 positions: Position one (If I'm understanding this correctly) is the B/W test setting and also the Red Gun test setting for when you're testing color picture tubes, then the second setting is Green, and the third Setting is Blue.

Now this is where I'm kind of confused in how this CRT Tester works and if maybe I'm doing something wrong and maybe why I came up with a "dead" red gun result in my test, the instructions for this tube tester makes it sound like there is actually supposed to be a 4th setting for the CRT emissions/Cutoff test but when I actually go to flip through the settings there's only 3 clearly discernable settings on the switch. The Instructions for the Cutoff/Emissions Test reads as saying that if you're testing a B/W Tube you leave the tester's test mode switch in the B/W setting but if you're testing a color tube you need to switch it to the Red setting and follow the directions for the test and repeat the directions for the Green and the Blue settings.

But there's clearly no separate settings for B/W and Red it acts like (and its marked as such too) that the B/W and Red test settings are one in the same setting on the CRT Tester.

Does anyone here have any experience with this particular CRT Tester or ones similar to this and if so how is it supposed to work, because the Instruction manual is leaving me with more questions than answers, and also how common is it for one single color gun to just randomly die on a TV when the rest of the color guns test super strong yet, and also is it possible that the picture tube is actually good yet on all three guns and I just wasn't testing the Red Gun Correctly?

Any help with this issue would be appreciated.

[Kevin Kuehn]

Originally Posted by vortalexfan

Now this is where I'm kind of confused in how this CRT Tester works and if maybe I'm doing something wrong and maybe why I came up with a "dead" red gun result in my test, the instructions for this tube tester makes it sound like there is actually supposed to be a 4th setting for the CRT emissions/Cutoff test but when I actually go to flip through the settings there's only 3 clearly discernable settings on the switch. The Instructions for the Cutoff/Emissions Test reads as saying that if you're testing a B/W Tube you leave the tester's test mode switch in the B/W setting but if you're testing a color tube you need to switch it to the Red setting and follow the directions for the test and repeat the directions for the Green and the Blue settings.

But there's clearly no separate settings for B/W and Red it acts like (and its marked as such too) that the B/W and Red test settings are one in the same setting on the CRT Tester.

You are correct. The 3 position switch simply selects which color gun you're testing. So you need to re-set the cutoff control for each gun when you move between the 3, because there's no memory of the 3 cutoff settings. Some fancier testers have 3 separate cutoff controls and 3 meters so you can compare all 3 color guns simultaneously.

[vortalexfan]

Originally Posted by Kevin Kuehn

You are correct. The 3 position switch simply selects which color gun you're testing. So you need to re-set the cutoff control for each gun when you move between the 3, because there's no memory of the 3 cutoff settings. Some fancier testers have 3 separate cutoff controls and 3 meters so you can compare all 3 color guns simultaneously.

That's what I thought but when I would go to adjust the red color gun settings and do an emissions test on the red color gun in my picture tube I get no needle deflection/movement from the meter but when I would test the green and blue color guns in my picture tube I get deflection/movement meter that shows that the picture tube is still good yet, but how is it possible for a picture tube to have really good testing green and blue color guns but a dead testing red gun?

[Kevin Kuehn]

Originally Posted by vortalexfan

but how is it possible for a picture tube to have really good testing green and blue color guns but a dead testing red gun?

Because they are 3 independent guns so there could be a mechanical failure of one component, and they can even wear out differently depending on how the drive controls were set.

[Kevin Kuehn]

But if you know all the guns work in the set, I suppose there could be something wrong with the red circuitry in the tester, right? Did you get a decent black and white picture like Zeno suggested? You could test a known good black and white crt to verify if the b/w, red switch position is goofy.

[vortalexfan]

Originally Posted by Kevin Kuehn

Because they are 3 independent guns so there could be a mechanical failure of one component, and they can even wear out differently depending on how the drive controls were set.

It seems kind of weird though that only one of the color guns would of failed catasctrophically but not the other ones, especially if it was a mechanical failure.

I was attempting to do a black and white setup on the tv and all I would get was a bluish green tinted picture with a slight bit of red in it, I couldn't really get the color to really go completely away.

Another weird thing is that the Color and Tint controls and the brightness and contrast controls don't seem to do anything with the TV and also the color adjustment and AGC Height and Vertical Linearity pots are acting like they might have tin whiskers because they do some weird things to the screen when I adjust them.

I have another Sylvania Color TV that is from 1974 that the tuner has failed on it, but it uses the same size of tube, and the picture tube was basically brand new on it because it was never used by the previous owner of it, I wonder if I could try to do a picture tube swap and see if it makes a difference with the TV?

[damen]

One dead or almost dead gun was very common when these types of sets were in daily use.

[zeno]

Do this. set the G-2 & drive controls to mid range.
Measure the CRT voltages & wright them down. Do NOT measure the
focus pin ! All 3 guns should be about the same. If one is way off
on the red find out why.
Another test. Turn the G & B G-2's all the way down. Bring up
the red & see if you get red. If you dont get red leave the set on
for 1/2 hr & see if it comes up with warm up at all.
Zeno

[vortalexfan]

I was also wondering if I could also attempt a pix tube swap between a 1974 Vintage Sylvania Color TV Console that has a bad tuner assembly but has a like new pix tube in it because the TV was never used by the original owners except as furniture. The parts TV has a 25" pix tube in it just like this one has.
I'll also try your suggestions as well Zeno, is there a specific voltage that should be present at the Red Green and Blue Pins on the Pix Tube? Is that info in the Sam's Folder for this set that I have?

[zeno]

Originally Posted by vortalexfan

I was also wondering if I could also attempt a pix tube swap between a 1974 Vintage Sylvania Color TV Console that has a bad tuner assembly but has a like new pix tube in it because the TV was never used by the original owners except as furniture. The parts TV has a 25" pix tube in it just like this one has.
I'll also try your suggestions as well Zeno, is there a specific voltage that should be present at the Red Green and Blue Pins on the Pix Tube? Is that info in the Sam's Folder for this set that I have?

Sams will give voltages & CRT pin ##"s. You are looking for something way off.
The volts wont be exact but in the ball park. EX is the G-2's can adjust
between 250 V & 800 V. if off by 20% thats OK. Looking for BIG diference.
The 1974 jug is probably a 25" viewable, the old one probably 23" viewable
so wont swap. Also about 1974 Sylvania CRT's only lasted a few yrs.
IIRC they were called "GT-Matics" & the main chassis was 3 large modules & the CRT was called "Dark Light".
Zeno