The Complete Zenith
By: Joe Sopko

From an unidentified Technician on one of the "Other" repair forums is a posting that covers many of the Zenith TV's from the mid '90's. They were plagued by regulator failures, and The Tech calims that if you check these items you will fix about 90% of all zenith's.

He also lists a method of isolating the Kine Filament, which was the cause of the Regulator failure in the first place. As our Technician population ages, and your memory fades, you might want to "Clip and Save" this article for when you say "Now, just what WAS that resistor in the regulator?"



1. ICX3431 = STR-53041 = ECG1840 = any generic is OK.
2. Q3431 = 121-1264-01 or -02 use ECG123 for 25" sets and NTE194 27" sets fast switcher. ECG194 is NOT the same not a fast switcher.
3. R3416 = 4.7 Ohm 1/2 Watt
4. RX3424 = 100K @ 1/2 Watt
5. RX3432 = 180K @ 1/2 Watt
6. RX3433 = 15 Ohm @ 1/2 Watt
7. RX3434 = 43 Ohms original sets use 1 Watt Later Models use 2 Watt
8. RX3435 = 10 Ohms @ 1 Watt
9. C3432 = 100/25vdc change this on any set in for service causes all kinds of problems.
10. C3434 = 22uf
11. Diodes Cr3431 / Cr3432 / Cr3433 check these with the Regulator and Transistor out of circuit easier.
12. Other Problems:
    CX3496 generally = 10uf @ either 315vdc or 350vdc.
    C2212 = 22/16vdc cause agc, pulling tearing, squealing, etc.

If the picture tube is shorted, try totally disconnecting and isolating the filament power supply from the flyback. Take some wire and out 2-3 wraps around the iron core on the flyback and use this for your filament voltage. Make sure to do away with any coupling or filter caps on CRT socket, as this has to be totally isolated, even if you have to cut or scrape away some of the copper foil. This will take care of a lot of the "blue screen", etc, cathode to filament shorts that continuously blow the power supply. Sure beats buying an isolation transformer!

"The Speaker" wishes we could give proper credit to the author of this artical, but on other Tech Forums, the members use only Nicknames for their screen name. We thank the "Mystery Tech" for this information, whoever he may be.

Below:
Letter To The Editor Concerning The Article Above

Letter From:
Herman Ackerman
Reynolds TV & Video Svc
San Diego CA 92116

I enjoy reading your newsletter and thanks for including me on your mailing list. Found a few problems in the April 2002 edition I thought I'd bring to your attention:

"The Complete Zenith" by the "mystery Tech".
He states "isolating the Kine Filament, which was the cause of the Regulator failure in the first place".

WRONG!! Virtually ALL regulator failures in these units are caused by a G1 short! I thought everybody knew that. This guy talks about installing turns of wire around the f/b transformer to save money on Isolation transformers. In fact, these devices are available for six bucks!

He also states "This will take care of a lot of the blue screen, etc, cathode to filament shorts that continuously blow the power supply".

WRONG! The H-K shorts will NOT blow the regulator! The G1 short is what blows the regulator, and isolating the filaments will not cure the problem.

---