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...

Its a MTZJ75-T2 no idea on the value

Watch the Yoke isnt shorted.


kip


"Bill S." wrote in message
...
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...

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.


In article ,
says...
Its a MTZJ75-T2 no idea on the value
Watch the Yoke isnt shorted.

"Bill S." wrote in message
...
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...

"Bill S." wrote in message
...
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.


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...

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:
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...

On 27 Mar 2006 15:45:32 -0800, "Dani" wrote:

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.



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

"Jason D." wrote in message
...


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

Cheers, Wizard


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!

Are you referring to R542?

In article ,
says...
This flameproof resistor is 1.8 ohms 1W