Zenith 19DC22 - Videokarma.org TV - Video

mkoser · #1 09-28-2009, 08:25 PM

Hello,

Yesterday I garbage picked a 19DC22. It's in pretty good shape, with the exception of the massive amount of dirt and dust on the chassis.

The set works, with the exception the focus is way way way out of whack.

Does anyone have any experience with a set like this, or a scan of the schematics I could take a look at?

My Sams collection doesn't go that new.

Thanks,
MK

radiotvnut · #2 09-28-2009, 10:23 PM

Let's see, that's a four tube hybrid chassis. The problem is most likely a defective focus divider resistor. The problem could also be a corroded focus pin on the CRT socket.

mkoser · #3 09-29-2009, 08:12 AM

Cool, thanks for the info. I'm still trying to track down a schematic.

Thanks,
MK

mkoser · #4 09-29-2009, 09:13 AM

BTW it's sams 1296-3

sampson159 · #5 09-29-2009, 10:54 AM

those are some great sets.when i was doing some repair in north columbus back in the 70s,we sold a ton of those zeniths.always an outstanding picture and were usually trouble free.change out the focus block and it could be the focus connector in the crt socket.like to have a dozen of them now!!please post pics

ctc17 · #6 09-29-2009, 05:59 PM

I think I have that set and the sams too. Mine has an arcing problem on the focus block. Where the hv connects to the focus board there is a 1 inch lead to a cap and it glows blue and sizzles. The picture is funky due to the arcing.

I will look and see if mine is the same chassis number of my sams.

bgadow · #7 09-29-2009, 09:25 PM

I have a spare; if you still need it send me your address.

mkoser · #8 09-29-2009, 10:04 PM

Here are some photos of the set.

As found:
http://farm4.static.flickr.com/3481/...ea72811452.jpg

before cleaning:
http://farm3.static.flickr.com/2539/...c962fb0cd7.jpg

after the first initial cleaning (still have a long way to go!)
http://farm4.static.flickr.com/3418/...0190da1325.jpg

Operating, bad bad focus.... I cleaned the CRT pins, and tried to adjust the focus. This is as best that it got.
http://farm3.static.flickr.com/2507/...e2c3b8538c.jpg

Any thoughts?

bgadow · #9 09-29-2009, 10:22 PM

I have this same set, but didn't realize it until I saw the pic. I haven't done a thing with mine-the repairman who gave it to me told me it needs a damper socket.

I don't know enough about the circuit in these to offer much. I guess I would start by measuring (if you can) the focus voltage. You may find it is non-existant.

radiotvnut · #10 09-29-2009, 10:24 PM

Let me guess, you have the focus control turned all the way to one end for best focus. I think you need a focus divider.

zenith2134 · #11 09-29-2009, 10:36 PM

Nothin' worse than bad focus.....well....

ctc17 · #12 09-29-2009, 10:54 PM

Mine is a 19cc22, I can scan it if you think it will help.

freakaftr8 · #13 09-29-2009, 11:13 PM

Wow!! That focus divider is wasted! Ran into this with 2 Zenith's now.. Seems that the sets are either hard on these or they are just a failure prone component. Does your focus pot even do anything at all? (does the picture get further out of focus the other direction you turn the pot)? If not it could also be a bad potentiometer. Had to replace onee of those too.. Zeniths have the stem hanging outta the back of the cabinets and could (rarely) get bashed in and screw up the focus pot.

mkoser · #14 09-30-2009, 09:12 AM

Hi.
Thanks for all of the replies.
The focus control is about 3/4 of the way "up". If I back it down, it goes really out of focus, if I crank it up, it gets slightly more out of focus.

I've never dealt with replacing/repairing a focus divider problem before. Can anyone briefly tell me what is involved?
This set obviously has no sentimental value, but I would make a nice shop TV.

I don't have a high voltage probe. I should buy one. Can anyone recommend one?

Thanks,

MK

kx250rider · #15 09-30-2009, 09:44 AM

Changing the focus divider is easy, if you can find one that hasn't gone bad from time and deterioration of the plastic... The anode cap has a phillips screw in it (contact side; between clip), and you loosen that and pull the focus wire out. The other wires are soldered to their destinations, and covered with a glob of silicone rubber (a must to do, or it will arc). However, what I always did, was to replace the high voltage tripler with a newer one (ECG 256a or NTE526a), which has a tap on it for the focus voltage, thus eliminating the divider altogether. Consult the schematic for a Zenith 19EC45 for the wiring change (simple).

Charles