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JVC AV-27850 What Part D422?

Anyone have a schematic/parts list handy for JVC model AV-27850 color television? The zener diode D422 on the output of the vertical IC was shorted (among other things) and I can't read any useful numbers from the part. Supply to the IC is about

28 Volts, which seems normal enough, and the flyback pulse on the output looked like around 50 Volts on my oscilloscope, so I tried a 1.5KE62A which shorted out immediately. So what part is supposed to go there? The original was a tiny thing, like 1/2 Watt or less, which leaves me wondering about such a high voltage...
Reply to
Bill S.
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Its a MTZJ75-T2 no idea on the value

Watch the Yoke isnt shorted.

kip

Reply to
kip

Thanks. Was shorted yoke a common problem on these? Set seems to be working, but hate to send it out without the Zener, which offers some protection.

Reply to
Bill S.

Protection from what... a short in the Hor. to Vert. yoke windings? Then the zener shorts and the vertical output IC blows regardless.

Most older TV sets never had a zener diode at the vertical output. The only thing it's good for, as far as I can tell, is for the repair business!

That zener will blow the vertical IC whenever that zener gets shorted. And it does that frequently but never again... if one cuts one side of the shorted zener and leave it in the TV that way.

--
Life is a funny school, where the tests are
given before the material can be studied...
Reply to
Do Little2

The Zener is a 75 volt value 1/4 watt.I don't, but some just leave it out! Also replace the 100 uf @ 50 volt electrolytic capacitor, check the

470 uf @ 50 volt, & solder all the secondaries from the flyback, as they get bad connections.

Bill S. wrote:

Reply to
Dani

This flameproof resistor is 1.8 ohms 1W

Replace this 75V zener also. This "protects" rest of circuits & yoke in event something went really wild.

Cheers, Wizard

Reply to
Jason D.

What "really wild" stuff do you (or anyone else) have in mind in order to justify this Zener diode as a useful part in this TV's vertical output?

Many thanks!

Reply to
Do Little2

Reply to
Bill S.

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