Just got a KCS-96 chassis set

[Aperna1985]

Originally Posted by jr_tech

Sounds unusual... how are you testing the caps?

jr

I have a heath kit C3 capacitor checker. I checked them all for leakage and everyone was leaky. Then I tried a brand new one and it tested good so I know my Checker is working. I did recap it in the past so it should be pretty stable

[jr_tech]

Originally Posted by Aperna1985

I have a heath kit C3 capacitor checker. I checked them all for leakage and everyone was leaky. Then I tried a brand new one and it tested good so I know my Checker is working. I did recap it in the past so it should be pretty stable

Thanks for the clarification... “leaky” rather than “open” makes perfect sense.

jr

[Aperna1985]

Originally Posted by jr_tech

Thanks for the clarification... “leaky” rather than “open” makes perfect sense.

jr

Honestly most were very leaky, like to the point where the tester would start to test then the eye would pop back open like there was no cap at all. but I did have 2 that were open.

[Yamamaya42]

Nothing unusual for old paper “bombs”, it would be more surprising if one checked NOT leaky and good.

[Aperna1985]

Hey guys I had a couple minutes last night to take a peek at the TV. I accidentally blew up the heath kit, I put it on the wrong terminal of the third IF and let the smoke out of it. So I hooked up the 1077 to pin number two of the 3rd IF and was able to pass a signal.,it wont lock, and there's a black bar rolling through it, there's also these white stripes going through the picture, almost like you were looking through louvers. They're not the usual light retrace lines they're dark lines a little more narrow than a number two pencil. I was able to pass audio through also. I did have to have the signal generator turned up all the way though to get an image. I went back to the second IF and tried injecting a signal on pin number one which looks to be the Grid on the Sam's and could not get any signal to pass I tried another 6DE6 that didn't help, so I assume that's where the problem is, or atleast one of them. I'm a little concerned that it could be a bad IF can and then this set becomes junk. I didn't get a chance to check voltages, we were going fathersday shopping and my wife wanted to leave. But I will follow up.

[Aperna1985]

I snuck downstairs for a few minutes today and had some interesting results. First somehow all the sudden I can pass signal through all 3 IF stages. I done know why that changed but it did. I still cant get the picture to lock and I still have distortion in the picture. The IF voltages are almost dead on to the Sam's except for the 2nd IF. According to the Sam's I should have 125V on pins 5&6 according to the RCA Schematic I should have 231 on Pin 5 and 252 on Pin 6. So I'm not sure of what to make of this. Then The RCA Schematic shows Pin 1 as having 113V where the Sam's shows -5V I have .03V, I'm not sure what to make of any of this....

[Aperna1985]

I spoke with a few people the consensus is that the RCA Diagram is right. I didn't take into account that the resistors aren't big enough to drop the voltage down from 255 to 125v. So I started tracing out Pin#1 of the 2nd If. the 150K 5% resistor read 189k so that is probably part of the issue. I only have a 30 MHz scope, If I just go through and change all the resistors, will I still be able to align this IF? I'm afraid to knock them out of alignment by changing all the resistors. I can tell someone else has worked on this IF board, so it maybe problematic. I would love to just put fresh Discs and resistors in here so I can set it and forget it ha-ha. But I don't want to be digging my self into a hole.

[Electronic M]

If you have the equipment (sweep marker generator and oscilloscope) and skills to do a television alignment replacing the resistors shouldn't be an issue for doing alignment (I've found on early color RCAs replacing the out of tolerance resistors often eliminates the need for alignment)... Though you need to use carbon composition resistors and not carbon or metal film resistors as the new film types often have somewhat inductive design that can do odd things at high frequency. Ceramic discs almost never fail so don't monkey with them unless they test shorted or open.

[Aperna1985]

A lot has gone on since my last post. I kind of wish I chronicled it a little better.

My iIF Board problems ended up being a bad solder joint. I could only find 5% carbon composition resistors through Radio Days and it took them a week to ship. So I got impatient and put the board back together. While I was at it I went through the board and reflowed every single solder joint just to see what would happen. I put it back together and all the voltages were dead on.

I set the TV up and my horizontal was going crazy. I asked advice from someone and he told me to adjust the horizontal coil and the horizontal wave form coil. Doing this got me a decent picture, but the top of the screen was twitchy. He told me that's probably the TV having trouble syncing. So I recapped the sync separator board, and at the same time I had lost audio completely so I recapped the audio board. I actually had open caps in both boards. I have to go through my notes to tell you guys which ones but it was very interesting.

At that point I turn the TV on and the horizontal was off again so I readjusted the whole horizontal. And had a pretty decent picture. I went to bed last night, the next morning I turned the TV on and had a complete loss of horizontal adjustment again, this time I could adjust it with the knob on the Tv, I added a picture of this down below. The picture is what the TV looks like every time you turn it on after it's sat overnight. If you turn it on and off while it's warm the picture comes back like nothing's wrong, and it doesn't lose horizontal sync the whole time the TV is on. But I have to set the horizontal everytime I turn the TV on.

The next thing is I tried to set vertical linearity for about 2 hours. Using the B&K 1077 slide I cannot get that circle around no matter what I do. The only way is to shrink the vertical so that there's an inch missing on top and bottom, otherwise it looks like an egg. I can't make the circle round is there a trick to this?

The last thing is the picture isn't very sharp and I'm getting these lines going left to right on the screen they almost look like the digital fake scan lines they add on YouTube videos and things like that to try to make them look old. Is there a way to fix that?

I made 3 youtube clips of the TV playing a DVD, and doing crosshatch. I also took some pictures.

Here's the B&K doing cross Hatch https://youtube.com/shorts/QKVGKsI1D...o0HzbUOCfrsj6l

Here's a movie playing https://youtube.com/shorts/jhDxmbxGC...ArAp8wsk8yosCy

Here's the same movie and I'm trying to make the picture sharper playing with fine tuning and a few things
https://youtube.com/shorts/DipkKuuvZ...S8ls9-kOJzibN7

[old_tv_nut]

Regarding: Here's a movie playing https://youtube.com/shorts/jhDxmbxGC...ArAp8wsk8yosCy
It looks like the brief intermittent could be an intermittent antenna or tuner connection. Time to wiggle wires and tubes and knock on various things gently with a screwdriver handle to see if you can make the set jump like this.

[old_tv_nut]

Regarding "sparkles" in the third video, I can't see them in your video. Do they look like they could be sound carrier dots (would dance around with the sound track)?

Edit: is the movie playing from a DVD? What happens to the "sparkles" when you go to a menu with no sound?

[old_tv_nut]

Regarding the circle distortion, some or all could be coming from the B&K.

Two ways to check:
1) (not the best) connect the B&K to a known good set and see what it looks like
2) (better) get a guaranteed good source, like a test pattern DVD.

[Aperna1985]

Originally Posted by old_tv_nut

Regarding the circle distortion, some or all could be coming from the B&K.

Two ways to check:
1) (not the best) connect the B&K to a known good set and see what it looks like
2) (better) get a guaranteed good source, like a test pattern DVD.

I'm going to try the test pattern DVD and start wiggling and tapping on the set. Any idea why I have to reset the horizontal every time I turn the TV on?

[old_tv_nut]

Originally Posted by Aperna1985

I'm going to try... and start wiggling and tapping on the set. ...

Just for a bit of fun trivia: at the end of the assembly line, Zenith (and other makers) had a final test where the set was pounded on three sides to look for any intermittents. Zenith used a kid's solid rubber ball mounted on a wooden dowel for a handle, and called this the "JWS" test, for "Jumps When Struck."

[old_coot88]

Coulda called it the 'GWT' test (glitches when thumped).