Craigslist Zenith Score! - Videokarma.org TV - Video

fsjonsey · #1 06-29-2011, 11:54 PM

I picked up my first all tube Color set today, from a seller in the Collinwood neighborhood of Cleveland. It's a 1966-67?? Zenith, still running on almost all of it's original tubes. On top of that, I found something interesting upon taking the back off the cabinet. There was what appears to be a space command tuner laying loose next to the chassis. It appears that the volume control also has a plastic gear drive attached to it, with happens to be cracked in two. The motor and space command receiver are missing, however. I'm guessing that the space command broke at some point in the past and was simply replaced by a manual tuner. Upon first power up, HV was very low and the picture bloomed and went out of focus as the brightness control was increased. A new 3DJ3 took care of that problem. The Electrolytic cans stay nice and cool, too! I'll post the model and Chassis numbers in a little bit.
Sorry about the poor quality iPhone pic. I'll post better photos soon.
Also, How hard would it be to find the missing Space Command components?

fsjonsey · #2 06-30-2011, 01:10 AM

This was the extra tuner I found laying in the cabinet.

DaveWM · #3 06-30-2011, 09:06 AM

sweet. cool cabinet. are the reds weak or is it just the programming (looks a bit weak to me)?

Sandy G · #4 06-30-2011, 11:03 AM

Kewl score !

fsjonsey · #5 06-30-2011, 12:05 PM

Quote:

Originally Posted by DaveWM

sweet. cool cabinet. are the reds weak or is it just the programming (looks a bit weak to me)?

It's the lighting and my iPhone camera. CRT tests strong on all three guns.

fsjonsey · #6 06-30-2011, 03:36 PM

Well, I have a problem. Went to turn on the set this morning, and a raster never appeared. I can hear some HV whine and audio, but nothing else. The set played fine all last night. Where would be an obvious place to look for a problem like this? I checked the HV rectifier, horizontal output tube, and damper, all tested fine.

Zenith26kc20 · #7 06-30-2011, 04:32 PM

Can you hear the high voltage "crackle" when it comes up? If so, look for the video output tube and see if it is lit. I have a similar chassis, different model that gives a nice picture.
Also, check your focus rectifier. I am not sure but on some sets no focus voltage can cause no raster.

fsjonsey · #8 06-30-2011, 04:49 PM

Quote:

Originally Posted by Zenith26kc20

Can you hear the high voltage "crackle" when it comes up? If so, look for the video output tube and see if it is lit. I have a similar chassis, different model that gives a nice picture.
Also, check your focus rectifier. I am not sure but on some sets no focus voltage can cause no raster.

Do you mean the crackle as the picture comes up and into focus, If so that's what I'm not getting. I'll check the focus rectifier, it's the green "stick" rectifier, correct? Just test it as a diode?

DaveWM · #9 06-30-2011, 04:59 PM

use a HV probe to monitor the CRT anode voltage

is the HOT red plating? wiggle the HOT and the horz osc tubes. hold a neon bulb near the plate cap of the HOT (I have one mounted to a small plastic stick).

I would pull the HOT plate cap off, check for B+, if that checks then I would put it back on and check the HOT grid for about -50v, screen voltage of around 150v. Also check the cathode current of the HOT.

This is where a tv analyst like a B&K 1076 comes in real handy.

DaveWM · #10 06-30-2011, 05:03 PM

you cant check the focus stick like a reg diode. You can just check the focus pin of the CRTwith either a meter like a simpson 260 on the 5kv setting or just a reg HV prob, the same as used in the CRT anode. Check to see around 5kv

fsjonsey · #11 06-30-2011, 05:09 PM

Quote:

Originally Posted by DaveWM

use a HV probe to monitor the CRT anode voltage

is the HOT red plating? wiggle the HOT and the horz osc tubes. hold a neon bulb near the plate cap of the HOT (I have one mounted to a small plastic stick).

I would pull the HOT plate cap off, check for B+, if that checks then I would put it back on and check the HOT grid for about -50v, screen voltage of around 150v. Also check the cathode current of the HOT.

This is where a tv analyst like a B&K 1076 comes in real handy.

The HOT is not red-plating, and has a mild blue glow. I don't have an HV probe right now, but will borrow one from a friend. Neon lamp lights near the plate cap of the HOT.