Avante Vertical Issue

[TinCanAlley]

Before I start pulling her apart I thought I'd stop by here and see if I'm going in the right direction with the current issue.

As of late, she's been a bit jumpy. The vertical size is twitching. The top and bottom 1/3 or so of the image move about half an inch in and back out. I'm thinking there is something wrong on the vertical module. Something affecting the V size or V lin.

So whatcha think?

[zeno]

Which chassis ?

Either one clean service switch & controls first.
Clean & re- seat module. Contacts can be tightened also.
IIRC there are few electrolytics on flat chassis.
IIRC only put an output in a flat chassis for no vert, never a
board.

Upright chassis you can use 9-92 or 9-147 module.
The newer 9-147 much better. BTW NEVER jump the vert fuse
on an upright chassis !

73 Zeno

[TinCanAlley]

She's an 25EC58.

When I went over the chassis, I removed all boards, cleaned contacts, boards and deoxit/faderlubed all pots, etc. She's been working fine (other than jailbars) for over a year now. Since the jumping starts pretty much right after turning her on, I don't think it's a heat issue.

The vert module is a 90-83.

[zeno]

OK flat chassis.
A few other things.
If it still has plug in transistors they can give
trouble. Also the terminal strips are soldered to the chassis
on the ends & sometimes along them. They use them for
grounds. They can break loose especially on older sets.
Thats it for easy stuff, try tapping around.....

73 Zeno

[rrrhre2s]

Try

C719 and C720 4.7 uf

Wet Slug Tantalum, Red capacitors... with one flat end...

Do not use a "regular electrolytic" capacitors they will cause linearity problems...

They are old enough to be going bad...

rrrhre2s

[Findm-Keepm]

My Zenith tech topics suggests for the 25EC58 chassis to resolder all the vertical output transformer leads where they meet chassis connections - particularly those on the top of the chassis. The symptoms described in the Tech Topics is vertical pull up from the bottom, with convergence affected.

[TinCanAlley]

I found this at Mouser. Is it correct? I sure wish there was a place local that carried such things. Gets tiring ordering a couple bucks worth of parts and paying triple in shipping.

http://www.mouser.com/ProductDetail/...nE%2f%252bI%3d

Originally Posted by rrrhre2s

Try

C719 and C720 4.7 uf

Wet Slug Tantalum, Red capacitors... with one flat end...

Do not use a "regular electrolytic" capacitors they will cause linearity problems...

They are old enough to be going bad...

rrrhre2s

[TinCanAlley]

She keeps her convergence with the twitching. Her top comes down a bit as the bottom comes up a bit. As it gets closer to the center of the screen, it gets less noticeable.

Thanks

Originally Posted by Findm-Keepm

My Zenith tech topics suggests for the 25EC58 chassis to resolder all the vertical output transformer leads where they meet chassis connections - particularly those on the top of the chassis. The symptoms described in the Tech Topics is vertical pull up from the bottom, with convergence affected.

[TinCanAlley]

I'll pull and reseat the transistors. Need to get his fixed as I have the final season of SWAT to watch as well as Movin' On.

Thanks!

Originally Posted by zeno

OK flat chassis.
A few other things.
If it still has plug in transistors they can give
trouble. Also the terminal strips are soldered to the chassis
on the ends & sometimes along them. They use them for
grounds. They can break loose especially on older sets.
Thats it for easy stuff, try tapping around.....

73 Zeno

[Findm-Keepm]

Here's all the tech topics for the flat chassis - three pages, something on all of them.

[rrrhre2s]

Originally Posted by TinCanAlley

I found this at Mouser. Is it correct? I sure wish there was a place local that carried such things. Gets tiring ordering a couple bucks worth of parts and paying triple in shipping.

http://www.mouser.com/ProductDetail/...nE%2f%252bI%3d

Those would probably work.

If you have electrolytic capacitors you can try them it will stop the jumping just height and linearity will no adjust properly .

rrrhre2s

[DavGoodlin]

Originally Posted by Findm-Keepm

Here's all the tech topics for the flat chassis - three pages, something on all of them.

Were these sent to Zenith Dealers? I never saw a format that gave credit like that before?

If so, the RCA dealers I worked for did not get anything like this.

Do you have any for 1964-72 color sets?

[rrrhre2s]

There was a guy selling yearly subscriptions to a repair list. He also sold one for the computer (386 - 486 Days). This was almost 22 years ago before I quit servicing TV's to make a living.

Used to carry them in a loose leaf binder for home service calls, sometimes saved loading up the set and transporting it back to the shop.

I now wish I had not gotten rid of them when I closed the shop in 1996.

rrrhre2s

[Findm-Keepm]

Originally Posted by DavGoodlin

Were these sent to Zenith Dealers? I never saw a format that gave credit like that before?

If so, the RCA dealers I worked for did not get anything like this.

Do you have any for 1964-72 color sets?

They are from Zenith's Tech Topics - I have an incomplete set from 1970 to about 1978. Doug (DRH4683) also has some - probably more than I do. Zenith provided these to authorized repair centers on a monthly basis, and we always picked up a stack at the Zenith training seminar. I went to a total of 2, but my father went to several dozen Zenith training seminars, and some RCA, NAP and even Sencore seminars. I got my Dad's collection of service data from his shop - mostly older stuff, as he sold anything newer than 1998 to another service shop when he retired.

RCA had their "Goldenrod" supplements - orangish-gold paper supplements to their service literature. I've got from CTC53 - CTC90. Later, Thomson issued complete field trouble reports - three types - TV, VCR, and Projection. I have all three for the CTC175-CTC203 era, along with all of their ESI disks and manuals, along with a Chipper Checker suite - almost useless today.

I've got Sony, Hitachi, LG, Motorola, Zenith, Philco, and Panasonic/technics, Samsung. NAP and RCA data, much more than Sams covered - and I still have my Sams (sets 100-1900) Anything newer from Sams, I don't have....

And thanks to Bryan Gadow, I even have Sears service manuals for 70s-late 80s stuff, but no index.

Cheers,

[Findm-Keepm]

Originally Posted by rrrhre2s

There was a guy selling yearly subscriptions to a repair list. He also sold one for the computer (386 - 486 Days). This was almost 22 years ago before I quit servicing TV's to make a living.

Used to carry them in a loose leaf binder for home service calls, sometimes saved loading up the set and transporting it back to the shop.

I now wish I had not gotten rid of them when I closed the shop in 1996.

rrrhre2s

There was a company called KDTV that had a database of repair tips for about 70 bucks, but 60 percent of it was useless crap like Sams cross references, model-to-chassis crosses, and parts subs. The remaining 40% was so Curtis mathes and Colortyme loaded that you got about 2000-3000 actual tips, and many were duplicates. They gave renewal credits for tips submitted, but no quality checking on the tips that were submitted, making for a very watered-down database. Repair World was okay, but got NAP heavy. Our best resource was other shops in our area, sharing helpful tips in phone conferences and a Sams-borrowing library. If you fixed a set, you marked up the Sams with the problem and cure. Some Sams had additional pages added - those were the problem sets like the System 3s, the GE AA/AB/AC chassis sets, and the RCA CTC175-185 sets with the EEPROM and tuner troubles.

Someone recently sent me a postcard about another online resource for an HDTV repair database - submit 20 tips and get a trial subscription. What a waste - board swapping isn't troubleshooting, and a database supporting that is not needed. Enough free resources exist - Vk, AVS forum and others for example.

Cheers,