Zenith Custom 23 Super H Chassis: FIXED

[Zenith26kc20]

If the vertical output transformer is shorted, unplug the convergence panel. I had both of my Zeniths (an M and an N) chassis fail identically. While waiting for a transformer, I could use them and get full sweep but outer convergence was terrible. Try to get a Thordarson transformer. They seem better built. I replaced both of mine with Thordason.
Is it the picture or is there a slight keystone to that raster? Keysone means yoke. Look for green corrosion on the youke windings. We changed a lot of Zenith yokes tears ago also.

[Kamakiri]

This one's a black and white, though

There is a slight keystone to the raster. The picture comes in clear and locks in sync, but it's only as high as the shot that I posted.

[Electronic M]

I always consider service literature a better thing to throw money at. I'd rather KNOW I need some expensive rare part and then get it, then waste my money depleting replacement stock for somebody down the road that does need it only to find out my set really did not need said expensive rare part and probably never will.

When you work smart you become a better tech, and spend less money replacing good parts.

[Kamakiri]

True. But at this point in the game, I'm trying to accomplish two things. I'm trying to broaden my knowledge, and I'm trying to get the set working. Many times, one comes at the expense of the other.

As with electronic automotive components, substitution with a known good component can yield the simplest diagnosis. More expensive, yes, but I'm okay with that.

[dieseljeep]

Originally Posted by Kamakiri

After replacing that suspect integrator and doing the filter caps, there's no change. Here's a shot of where I'm at now.

I've been advised that the next step is a vertical output transformer, so I'll be giving Moyer a call this week....

Is that the 23" Zenith that uses the 110 degree CRT? All Zenith's 23's, after that used the 90 degree CRT's. Large neck.
I'd put my money on a open vertical winding in the yoke, especially if it's the 110 degree yoke.
If it's the 23", 110 degree model, it's an odd-ball. IIRC, they only made one year of them. There must've been a reason!

[Kamakiri]

Picture tube is a 23ZP4. Looks like a 90 degree to me, it's a BIG HEAVY tube.

[Zenith26kc20]

Is the yoke a 95-1610? If so, I have changed a few of them. It goes to a Stancor DY-13A. If you remove the yoke from the neck, you will see green corrosion on the windings. This seems a problem with some sets.

[dieseljeep]

Originally Posted by Kamakiri

Picture tube is a 23ZP4. Looks like a 90 degree to me, it's a BIG HEAVY tube.

IIRC, that's the first year for that CRT and the big heavy front glass panel.
I keep forgetting those sets are 50+ years old and subject to large component failures.
Remove the CRT and inspect the yoke windings, as suggested. Take resistance readings of the vertical windings. They should both be alike. Around 15 to 25 ohms. If there's resisters across the windings, disregard them. If the winding is open, you'll just read the resisters.

[Kamakiri]

I'll have to do that when I get chance, but I went to take a picture of the yoke, just to show, and I noticed what appears like a burn mark in the plastic cover. You can see it in this picture as a white spot, but in that white spot it appears to be melted.

Hm.

No visible marks that I can see, but again I'll have to pull it anyway. Good thing is that Moyer does stock the yoke.

[Kamakiri]

It was the yoke. Replacement came in from Moyer, and I installed it right away. I'll have to dial in the rest of the picture adjustments tomorrow when I can get a flat bladed screwdriver that's thin and about 8 feet long to reach the linearity and height controls on the chassis

But tonight, gentlmen, I get to watch TELEVISION!

[Kamakiri]

Originally Posted by Zenith26kc20

Is the yoke a 95-1610? If so, I have changed a few of them. It goes to a Stancor DY-13A. If you remove the yoke from the neck, you will see green corrosion on the windings. This seems a problem with some sets.

Yoke was actually a 95-1654, which crossed to a Thordarson Y98. Same yoke also fits 95-1768, 95-1825, 95-2093, and 95-2383, with one exception.....there's a white wire that goes to a 1 megohm resistor that isn't used with my set. Didn't see any corrosion or really anything noteworthy on the inside of the old yoke.

[Kamakiri]

Got it dialed in nicely. The Brady Bunch looks pretty darn good

Put the back on, and I call this job done

[Celt]

Very cool!

[El Predicta]

The pattern looks wedge-shaped. How about the deflection yoke?

[El Predicta]

Sorry- for some reason didn't see all the previous posts!