No picture on a 1979 Zenith 25kc45.
 

Im rather new to this so i’ll apologize in advance if I’m stupid. I got a Zenith Chromacolor II (chassis 25kc45) a bit ago and i checked that none of the parts looked obviously bad and lightly cleaned it. It served me well for about a month until i went on a cumpulsive polishing spree. I hit several things including this tv. Well, unbeknownst to me i had accidentally ripped the black wire that runs from the trippler to the crt out of the trippler. Well when i put it back together and went to redo convergence and such there was no static, just white that got brighter and brigher until the crt started arcing inside and i unplugged it. I later found my mistake and resouldered the wire, however there still is no picture just a blank raster. I have no control of brightness, contrast, either of the focuses, of any of the screens. I presume the crt is being drivin at full force as the guns and raster are alarmingly bright. The sound however is fine this is purly a video problem. I dont think that its compacitor related as it worked beautifully before i broke it. If it isn’t too much of a bother could one of you please help me figure out whats wrong with it?

Your first order of bussiness should be to take an HV probe and confirm your HV and focus voltages match that listed on the schematic. (I may have the schematic if needed) If the trippler was run with a wire removed it may have been damaged.

Next order of bussiness once the above is dealt with is compare the gun bias voltages to the schematic and see why your brightness is excessive. Trace found voltage annomalies back to source. Once brightness is sane if you still don't have video use an oscillo scope to trace video from the detector (sound is usually split from video IF just past video detector) forward towards the CRT and look for the point you loose it....Or inject video from a service test pattern generator from to the CRT and work your way back towards the detector till you loose it. Once you have identified the point it drops out at sart testing components and voltages there till you find something.

The only part of the inside of a CCII that needs to be clean is the electrical contacts (modules, tuner, pots, etc)...When these sets were new more than one was left on in house fires and continued to run after the fire was put out...Perhaps my favoirte story of such a set the outlet stayed on and the front of the set was completely covered in soot, speaker cone burned, knobs melted, etc...The firefighters noticed a flicker at the edge of the screen and wiped the screen to reveal a perfect TV puicture beneath the soot...CCIIs don't die without as much help doing so as they can get.

Nevermind, i asked my dad to help me move it and in his haste and stobborness he freaking necked it

Jeez...That is a $150 CRT replacement. You should insist he pays for it.

From where. I was under the impression that crt replacement for older than the the 80 was finding a needle in a haystack and paying $200 for it

CRT was already fried, might as well neck it!

Save the chassis. Many parts fit in sets going back 6 years
on 13" - 25" sets. Wont be hard finding another. They were the
most sold sets in the US back then & they are almost immortal.
Just be careful of part numbers. Some things look the same but arnt !

73 Zeno:smoke:
LFOD !

Depends on the CRT type and size in your set.

Almost all deltagun CRTs the Same screen size interchange. The main thing to be careful of is getting the right screen size. In 1968 the government passed a law that CRT size had to be viewable area instead of outer bulb diagonal...so a 1965 25GP22 became a 1968 23VGP22... Most tubes post 1968 with the viewable designation will have a V as the first letter. But I'd recommend looking up datasheets and doing a comparison (if things don't jibe ask us since some differences can be fudged).

Bob has under CRTs for sale a 25EGP22 (pretty sure it's a pre 1968 number) that should sub for 70s 23V types. http://antiquetvguy.com/FramesetPage...FrameSet1.html

If you are near enough to me to come pick it up (I don't mail CRTs) I have a good used 25V deltagun out of an RCA that I'd sell. I have 23Vs too but I have so many sets that use them that the only spare I'd part with probably needs a brightener.

The ETF has some color CRTs for sale too.

I think you skimmed his post a bit shallow. He said he was still getting blank white raster before it got necked... the tube was fine till it got necked.