Scored ANOTHER 25DC56!

[zeno]

Good way to clean turret tuners is with a big eraser. Pop
cover off & turn channels, moving along as you go.
If one is still flaky bend up that strips contacts a VERY
little bit.
Can also tune an adjacent such as ch 3 on ch 2 or 4
most the time.

73 Zeno
LFOD !

[Jon A.]

Ha, yeah, I once fine-tuned my own 25DC56 to pick up a local FM station. Lots of static, but not too bad. I had a CTC117 with an electronic tuner that was probably a little better at it though.

[TUD1]

Yes, I should have mentioned that. When I got the set, I cleaned all the contacts inside the tuner very thoroughly with Radioshack cleaner and lubricant, and I wiped the contacts clean with a smooth rag. I take cleaning very seriously. It worked perfectly last night for two hours. Got up this morning, and I saw this mess...

[Electronic M]

Originally Posted by TUD1

Yes, I should have mentioned that. When I got the set, I cleaned all the contacts inside the tuner very thoroughly with Radioshack cleaner and lubricsnt, and I wiped the contacts clean with a smooth rag. I take cleaning very seriously. It worked perfectly last night for two hours. Got up this morning, and I saw this mess...

Did you use the RS stuff that comes out as a sort of semi-frozen oil...IMO that stuff is nearly useless on it's own. Your better off with the eraser (white drafting works better than pink), or better yet combine a good cleaner with the eraser. There is a product called De-Ox-ID that you can get online for <$7 for a decent sized can...It is as good as Deoxit, but less than half the price.

[TUD1]

Great news. I adjusted the AGC Delay pot like Danny said to do, and it hasn't had the problem since. That's not to say it won't crap out again soon though. Only problem now is that sometimes the horizontal won't lock. The horizontal hold is all the way to one side.

[zeno]

For hoz check the 330 ohm on the 9-57 board.
Use a 1W film. This is the same as on the 9-90
in upright chassis 25EC45 etc, very common.
For control pull out the white sleeve over the shaft
center control then center the sleeve. Almost all
Zeniths have this in one form or another.

73 Zeno
LFOD !

[TUD1]

Been watching the 25DC56 for about ten days now, and surprise, it's got a new problem. Intermittent red. It usually will work good after half an hour, but the before that, it comes and goes, and is very streaky. I'm thinking bad transistor, or at least a bad connection somewhere.

[Electronic M]

There should be a trio of color video output transistors....Swap the red and blue OR the red and and green....If the color you swap with becomes intermittent the transistor is bad....I had such a transistor failure in a 71 zenith hybrid, and diagnosed it that way.