Zenith Cromacolor 2 or System 3?
 

Hi everyone.
I just had the luck to find this beautiful Zenith tv in my country and find those magnificent pieces of american craftmanship is not easy here.
Unfortunately the tv doesn't work. Inspecting it before giving it power revealed a blown out electrolytic. I removed the horizontal module (9-153) and found several other components dead. I'd need to know the exact type of the chassis. Informations found on various sites gave controversial advices. On front side there is clearly marked "Zenith Chromacolor II" but it has not the usual Chromacolor vertical or Horizontal chassis. It has a large power transformer but this chassis resembles much more to the System 3 chassis.
I found several NOS replacements for the horizontal module (9-153) but it appears there are several types of the 9-153 module. I found a 9-153-03, a 9-153-11, 9-153-12 and 9-153-13. Which one is the correct one? Any advice from you Zenith experts would me more than appreciated. I would like to restore it at its best as it witnesses a time where things were made to last.

What you have is the first year of the System 3 chassis.
Before that they used a steel chassis with modules.
This chassis was only built for one year the K line, 1979 IIRC.
You could get it in 19" & 25" with or without remote.
After that they combined the HV & power supply onto one
board with a very complicated design. The rest of the sets
modules were much the same. It was one of Zeniths best chassis.
The only improvement was you could get a comb filter &
digital tuning on the newer ones. Very reliable & excelent color.
I can not say anything bad about this set & I sold many of them new.

The main problems were:
Cold solder under the hoz drive transformer (9-153)
sometimes would blow hoz output.
Bad 24 V regulator IC.
Bad connections on 9-155 at outputs, CRT socket & resistor package.
Big cap across the power transformer ( oval one ).
Electrolytics in vert out.
Electrolytic in 200V supply on 9-153

A great find in Italy, must have come over with a military man or did Zenith
sell in Italy ? If I can help more feel free to ask.

best 73 Zeno:smoke:

i have one of these sets with an excellent crt.it does have that horrible vertical tuner that gives us all fits though.the picture is amazing.

Probably left by someone stationed either at Camp Darby near Livorno, or stationed at Aviano in NE Italy. Also lots of abandoned (broken) sets in Naples - I remember walking by a dumpster at NSA Naples in September 1986 and seeing a few busted up sets inside, probably tossed by the Navy Exchange or their contracted repair folks. Somewhere around here I have a Telefunken output transformer I got there - it was for an import set my dad was working on. I paid, and they shipped it to the states for me.

An NTSC Zenith in Italy probably only picked up AFRTS (on-base) or Satellite service (off-base, or at one of the TLAs).

Cheers,

We'd need to know the model/chassis, so the CRSP book could be referred to - the CRSP lists all chassis/module combinations and possible substitutes. I have an older one, but know of a dealer that has one too, possibly newer than mine. Post the model/chassis number and I can help. Also, I can post any tips I may have for that chassis, similar to what Zeno has already provided.

Cheers,

Hi and many thanks for the useful notes. The horizontal module has the
Horizontal output transistor short circuited. There also is a completely open diode and an exploded capacitor. The resistor behind is splitted in two pieces. I can read the model, it is J2546PN. I downloaded the schematic from the sams website but it doesnt match the chassis i have in my set. I can't seem to find the chassis number anywhere . I would like to buy a new horizontal module but which type? Are there several kinds of this module or are they completely interchangeable despite the fact last figures are different? Thank you very much for the help! The tv was brought here by a guy who lived in chicago. When he decided to get back to Italy he decided to bring the tv with him. It was anyway an useless piece of furniture since there was no way to modify it for our tv standard. Now with digital tv things are changed and i am perfectly capable to get an NTSC M signal out of my set top box and use the Zenith like every other old tv.

Since this set says "Chromacolor II" on the front and the model number shown on the back is from the "J"-line, I wonder if this cabinet originally had a steel CCII chassis in it and, for whatever reason, someone installed a newer chassis in this cabinet? Can you post a picture of the back cover? I can look at the original back and tell you if that back was made for a vertical CCII chassis or this system 3 chassis.

These are the pictures of the back cover and labels. I downloaded the service manual of a tv with similar chassis but the defective components do not appear on the schematic.

You wont find a chassis number, they stopped using them.
Its a mystery why its a J model, maybe they started using
them at the end of the J line, I dont remember. There were
also sets released regionally first, digital system 3 & Bose
sets IIRC. The CC 2 marking may be just before they came
up with the system 3 name. Also had limited availability sets,
I tried to get the first HDTV for one of the Boston TV
stations. A $10,000 projo, just couldnt get one even for
them. But there may be more to that.............

I will look up a K line later & see what the parts are that
smoked up.

73 Zeno:smoke:

I forgot the pictures...

Thats the right back for a system 3. A CC2 back would
have a plasic part with AC interlock & control holes.
Maybe someone has the OEM Zenith manual to solve
the mystery or a J line sales folder.
Back in E line they replaced the flat chassis to the new CC2
mid line & never told us. Found out by accident months
later.

73 Zeno:smoke:

Zeno do you know by any chance the difference between the various horizonal modules? I have to order one new but i don t really know if the last numbers make a difference or not.
Thank you very much

After seeing all the pictures, I'm going to have to say that you have a very early System 3 with a CCII badge. I agree that this set was probably made just before they started using the System 3 badge.

I know that some versions of the 9-153 were used in Zenith's early projection sets and the HV modules for the projection sets have a different style of HV connector.

After a quick look at the schematic i noticed the damaged components (R3379-C 3377) are directly connected at the source of the 260V (tap J of the flyback). 260V directly powers up the video output transistors. I think there was a huge power surge and I really hope it didn't damage other components on other boards.

Replace the resistor, the capacitor, and the diode that feeds B+ to the video output stages. Then, use an ohmmeter to test from the 260V B+ line to ground. If nothing is shorted, you'll probably be back in business.