Help removing jail bars from Zenith 19JC55Z

[TinCanAlley]

Originally Posted by radiotvnut

I'm pretty sure the boost filter is inside the multi-section power supply filter cap. If so and if that cap is bad, you'd be better off to replace the entire capacitor with individual capacitors. Trust me, I've learned this the hard way. One section of a cap will be bad, I'll isolate the bad section and add a good cap to the circuit, and then another section will fail in a week.

And how would one go about finding the multi-section cap? My best guess is that it's on the same side as the tripler, etc. Any clue as to what it might look like?

Thanks!

[radiotvnut]

It's a tall, round silver can on the flat part of the chassis, next to the power transformer.

[wb2mep]

From your schematic, it looks like it would be CX228, the 10 uF 350 V cap located below the HOT on the schematic.
It's a standalone cap, buried in the chassis, not on a module. It filters the 250 V that powers the video outputs on the 9-121-01C module.

[TinCanAlley]

Okay, it's been awhile, but I'm finally getting around to working on this problem.

I've replaced the 10uf 350v cap (it measured out at only 4uf and appeared to have leaked some time in the past), so it was bad. While I was in there, I replaced other axial caps and removed the canister. The canister tested good, but I'm taking it to my brother's for testing with his ESR (or what ever that thing is called). I found a place that has an NOS canister, but I don't trust that after all these years it will be worth trying. I have purchased all the caps that are inside the canister and my brother will open it and replace all of them and put the back in the canister.

Let's hope this does the trick, because it started getting worse. The left 1/3 of the screen would have nice contrast and brightness, but the right 2/3 of the screen would be way too bright until it warmed up and then they would almost even out. It would still show the jail bars, though.

Anyway, I appreciate all the help and I'll let you know how it goes. Should be done by Friday.

[Dude111]

Good luck buddy!!!

I was thinking those bars MIGHT HAVE BEEN some kind of interference and i was gonna suggest moving her and see if they were still there.. (When our neighbour used to key up his radio in the house next door many years ago we got similar RF interference on the screen which is why i wondered)


I want to wish ya the best of luck getting her fixed!!!!

[TinCanAlley]

Success! No more jail bars and no more uneven brightness across the screen!

So it seems it was the 10uf 350v cap, only. I tested the canister and it was good, so I put it back in.

Upon firing her up, no smoke, not sparks and no blown fuses. Yea, I didn't mess anything up while in there (not that I normally do that).

The only thing I had to do was run DVD Essentials and calibrate the brightness and contrast again. Picture looks beautiful!

Thanks to all here. You make my repairs a success with your input.

[holmesuser01]

I love the Chromacolor sets. Always have. Never have I owned one, though.

[Dude111]

Congrats my friend!!!!!!

Give her a pat for me would ya??