This set has always had jail bars to some extent. It was initially recapped because of other odd video issues associated with bad caps. Once the recap was done, the bars were more noticeable once brightness and contrast were set.

I have replaced C258 with the SM replacement part from Vishay. C264 tested good with and ESR around 430 milliohms and a value of 45. I have a replacement, just in case.

I've been trying to figure out where to inject the signal from my generator, but lack the knowledge of where in the circuit to inject it and what I need to disconnect when doing so.

Years ago, you can search for them, I posted quite a bit during the initial repair and search for ringing source. I used the scope of many areas and found ringing in a couple, but was told that it wasn't the cause of an issue. Found it in the brightness limiter circuit, HOT base and B+, but I was pretty new with the scope and I went with it not being the jail bars. The waveforms in the Sams aren't the highest quality, but enough to note difference is what I got.

The set has the original tripler. Only thing it need was the focus divider and I got an NOS and it's been fine ever since.

Once the set is back up and running, it's going to need some adjustments, so I thought I'd run through all the adjustments for AGC, ACC, APC, brightness limiter, color killer, convergence (static and dynamic), etc. Not going to mess with the IF stuff, just the basic stuff. Just wondering if the factory SM has the same procedures.

Thanks for all you time and help!

Well trying to test all the pots on the convergence board isn't going to work. I was able to test 3 correctly. Those 3 had correct values and smooth readings. The other 6 didn't show anything useful. I'm assuming it has to do with those 6 being tied into a bunch of resistors, diodes and many connected to each other. One started around 1ohm and gradually moved up to almost 30ohms, but instead of continuing upwards, it started to go back down and was almost 2ohms at the other end. I know this isn't supposed to happen, so it must be the other connections on the board interfering?

So I just gave them another dose of D5, followed by multiple turns and finished up with F5. If that doesn't help, I have several new pots I can install, but will need to get some Mallory pots noted in the SM as I can't find the ones I don't have. What I find odd is there is one pot that has specs of 120ohm 2W, but it has a different part number than the other three 120ohm 2W pots on the board. They all feel wire wound, so I wonder what the difference is.

Topside is done. It has all new transistors (2nd and 3rd video amps, brightness limiter, vertical blanker, blanker and video outputs). Might be a little overboard, but I had access to them, so why not. Also used contact cleaner on all the modules and IF contacts as well as all contacts in the plugs. With the replacement video outputs I was able to reinstall the original heatsinks and support cage.

In the horizontal blanking, all the resistors were replaced and the diode tested good. Is it possible for a diode to test good and be weak?

While troubleshooting by substitution can be a strategy, replacing large swathes of parts can have a real risk. At some point in time you can find yourself with a set that doesn't want to work right, and unraveling layers of parts and changes can be extremely difficult.

In the end this is your set and your journey!

Always wait for the DeoxIT to evaporate and dry before you energize.

Diodes can be leaky, the horiz blanking diode CR201 would be a good part to substitute. This needs to be a fast switching diode like a ECG177.

I would take some time to look at the voltages on the Blanking Amp Q202, Vertical Blanking Amp Q217, and 3rd Video Amp Q203. The line between the collector of Q217 to the base of the Blanking Amp Q202 gives you a perfect place to scope the blanker at both the vert and horiz rates. Good waveform to look for in the SAMS. C204 and C202 are critical to horiz blanking.

Were any of the resistors in the Blanking circuit out of tolarance?

Out of curiosity does the Peak Pix control work?

Does this set have a separate focus divider?

Do you have the shield for the Subcarrier module?

Each of the subs were tested earlier in the set. I swapped them in and out until I was certain they all worked as expected. Just never go around to doing the permanent swaps. Now I have and it won't be hard to figure out which one if any fail. I still have all the previous parts.

I can scope them again. I did this back in 2013 on all those outputs and they measured at rated voltages. I also replace CR201 back then and still have the one I removed as the new one didn't help issues, so the old one is still good. Last go around I replaced the 750V Boost diode, Damper diode and Horizontal Blanking. The only other diode I was supposed to change, but didn't, was CR202 Zener Diode 24V across the emitter and collector of Q204. I have that diode and it would be an easy swap.

I'm going to order those two capacitors you noted as I was eyeing them myself, but is wondering what other pieces I might want as I'd like to maximize the order to justify the crazy shipping rates now.

The peak Pix works, the resistors in the horizontal blanking circuit were replaced and it does have a separate focus divider. I replaced that shortly after getting the set as it would sizzle on humid days and upon inspection it was drying and cracking.

This is the alternate module (9-69) for this chassis and it doesn't require the shield. If you look closely at the board, there is a shield around the sensitive section only. I think the cover is the reason the pots on the original were messed up. They were poking through the holes for make adjustments and messed the up. They were pretty mangled.

Do know if this set will run with the video IF module removed? If so, I can connect my generator's signal via it's injector connection directly to the C1 test point into the video amp section. I am unsure if connecting my generator to this point while the IF is working would be a bad thing as it seems there's roughly 6V on it. This would let me see if the jail bars are being injected from the IF stage.

I believe you can run this set without the IF module in place. The 125v B+ supply interlock does not run through the IF module. You wouldn't need to feed a signal to the IF output, you should still have a raster. You might need to turn the brightness up a bit to see it.

If you are going to replace C202 in the horiz blanker, it needs to a temperature compensated N750 Capacitor.

If by the IF output you mean connection 5 on the IF module (Video-Sync-Chroma), that's where TP C1 is located, so I could clip the lead of the generator onto that point on the top of the chassis.

I have the two capacitors in my cart now and they are the part numbers from the SM and the C202 replacement is N750.

Here is the section of the generator instructions related to injecting the video signal. Maybe it will help identify exactly where it should be connected.

I'm assuming you have the set back up and running, and the jail bars are visible.

Try this:

1) Gently disconnect the IF Input cable from the tuner to the chassis. At the chassis it is very similar to an RCA connector. Power up, jail bars still visible? Power down.

2) Remove the IF Module. Power up, jail bars still visible? Power down. Leave the IF Module out.

3) Drive the video stages with one of your generators. Most generators will block a small amount of DC but to be safe, connect the 50 Ohm video output through a .1 uf or so capacitor to block the DC. Connect to the C1 test point you have identified. Shield to a nearby chassis ground. Power up, adjust video level from the generator, try different patterns, what do you see?

Safety-- This is a transformer based set, so you should be reasonably safe using grounded test equipment, unless something is seriously wrong.

I appreciate my Sencore PR57 everytime I use it:yes:

Set isn't together yet. I'm waiting for the C202 and 204 replacements. Am also going over everything under the chassis to make sure I didn't disturb something and create a short. Once that is done, it goes back together on Monday or Tuesday, depending on delivery of parts.

The instructions with the Hickok says to ground the generator by connecting black lead to chassis. I wish it had more details on that since I had assumed the black lead went with the red lead which is the trigger out for my scope. That and I'm sure it needs another adapter of sorts as my scope's trigger input is a 1Mohm 20pf BNC. But that's another day's battle.

Tried to pull C202 and 204 by heating up the bucket and pulling the leads out, but that only worked on one lead that was alone in the bucket. All the other leads were in one with multiple leads and I couldn't seem to get it hot enough as they all acted as heatsinks. So I cut the other leads.

I tested them and the 68pf tested as 56pf with an ESR of 21kohms and the .0047 tested as .0038 with an ESR of 411ohms. I tested them for value at 100Hz and ESR at 100kHz. That is correct? When the new ones arrive, I'll check them the same way.