Zenith D4760X91 Service Manual Needed

[Macdude]

Hi, does anyone happen to have the zenith service literature for this model? I have the SAMS for the chassis (25DC56) but I would like the original Zenith paperwork/pdfs if I can find them. I'm slowing working through this set.

Thanks!

[JohnCT]

Originally Posted by Macdude

Hi, does anyone happen to have the zenith service literature for this model? I have the SAMS for the chassis (25DC56) but I would like the original Zenith paperwork/pdfs if I can find them. I'm slowing working through this set.

Thanks!

I threw all my Zenith stuff out years ago except the condensed single page schematics that Zenith sold us in one large book (mostly SS).

Zenith schematics were fairly well organized, but the nice thing about SAMS is that they always laid out every schematic in the same manner for every manufacturer, and were easier to read and very accurate. They often gave you more voltages and waveforms than most manufacturers supplied. Unless you want them just to have (I understand), you might find the SAMS easier to work with.

John

[Macdude]

Originally Posted by JohnCT

I threw all my Zenith stuff out years ago except the condensed single page schematics that Zenith sold us in one large book (mostly SS).

Zenith schematics were fairly well organized, but the nice thing about SAMS is that they always laid out every schematic in the same manner for every manufacturer, and were easier to read and very accurate. They often gave you more voltages and waveforms than most manufacturers supplied. Unless you want them just to have (I understand), you might find the SAMS easier to work with.

John

On one hand I'd like to have it just to have it, but on the other I was thinking maybe it would have more info on the unit as a whole, but I won't go crazy looking for it now.

Thanks!

[Electronic M]

Zenith offered both single page schematics and full repair manuals. The full repair manuals were more detailed than Sam's but aren't easy to find.

I only have a few manuals for random chassis, but nearly all the single page schematics for color...I don't let go of the originals, and scan/copy isn't practical currently.

[zeno]

Zenith factory manuals show up on e-bay often.
They are marked CM###. Supplements will be marked
CM### s-1 etc. Sometimes there are separate tuning system manuals
marked TS##. Since your Avanti has click tuners you dont need
that. IIRC the D-line manuals were about CM120.

The big thing with this chassis is to CHANGE ALL the 22-5001 caps
that are white. Orange ones are OK. IIRC there are 2 on the FBT & 3 more under the chassis. Must use the right sub or they WILL short.
They open & the HV goes up a few KV for each one. That will kill
the tripler, divider & CRT socket. HV can reach 4++0-50 KV if all go bad.
You should see the lightning show

73 Zeno
LFOD !

[Macdude]

Originally Posted by zeno

Zenith factory manuals show up on e-bay often.
They are marked CM###. Supplements will be marked
CM### s-1 etc. Sometimes there are separate tuning system manuals
marked TS##. Since your Avanti has click tuners you dont need
that. IIRC the D-line manuals were about CM120.

The big thing with this chassis is to CHANGE ALL the 22-5001 caps
that are white. Orange ones are OK. IIRC there are 2 on the FBT & 3 more under the chassis. Must use the right sub or they WILL short.
They open & the HV goes up a few KV for each one. That will kill
the tripler, divider & CRT socket. HV can reach 4++0-50 KV if all go bad.
You should see the lightning show

73 Zeno
LFOD !

Great to know about the service literature, thank you. The first thing I did was change the remaining white 22-5001 to the Sprague orange drop version. There is one remaining cap on the flyback that’s a .68 or so (NOT a 5001) however it’s a Packtron brand which I’ve heard lousy things about. I’ve had no luck finding 22-5001s en mass so at the recommendation of a knowledgeable friend I bought some Kemet .0018uF 2kV pulse rated film caps as a replacement.

[JohnCT]

Originally Posted by zeno

Zenith factory manuals show up on e-bay often.
They are marked CM###. Supplements will be marked
CM### s-1 etc. Sometimes there are separate tuning system manuals
marked TS##. Since your Avanti has click tuners you dont need
that. IIRC the D-line manuals were about CM120.

The big thing with this chassis is to CHANGE ALL the 22-5001 caps
that are white. Orange ones are OK. IIRC there are 2 on the FBT & 3 more under the chassis. Must use the right sub or they WILL short.
They open & the HV goes up a few KV for each one. That will kill
the tripler, divider & CRT socket. HV can reach 4++0-50 KV if all go bad.
You should see the lightning show

73 Zeno
LFOD !

Good call. Those caps caused all sorts of issues. Zenith issued a bulletin about them. Eventually, we just started shotgunning them.

John

[Macdude]

Originally Posted by JohnCT

Good call. Those caps caused all sorts of issues. Zenith issued a bulletin about them. Eventually, we just started shotgunning them.

John

What about the white ceramic tube Elemenco(?) caps? Worth replacing as a rule as well?

[Macdude]

Also picked up a CM-121 booklet on the auction site which covers the 25DC56. Thanks for that tip!