1950s or '60s vintage Zenith TVs, Need some info

[vortalexfan]

Originally Posted by init4fun

Private Pyle !!!!!! What part of this do you not understand !?!?!?!?

Ok, well where would I source a new circuit breaker for this TV?

[init4fun]

Originally Posted by vortalexfan

Ok, well where would I source a new circuit breaker for this TV?

Dude, your not trying hard enough here, and I'm not usually one to do someone's homework, but since ya asked nicely, just this once I'll give ya a hand ;

This is one listing out of a few I found while searching "Replacement Circuit Breaker for vintage TV" ......



https://www.ebay.com/itm/352518574185

[vortalexfan]

Originally Posted by init4fun

Dude, your not trying hard enough here, and I'm not usually one to do someone's homework, but since ya asked nicely, just this once I'll give ya a hand ;

This is one listing out of a few I found while searching "Replacement Circuit Breaker for vintage TV" ......



https://www.ebay.com/itm/352518574185

Ok, take at easy dude, I was asking because I thought you were suggesting that I was going to find them brand new somewhere which I wasn't sure how that was going to be possible seeing as TVs haven't had circuit breakers in them like that since the 1980s, I didn't realize you meant going to ebay and finding a NOS circuit breaker.

This is the first TV I've worked on that had a circuit breaker on it so I didn't know... 😶

[Electronic M]

One "safe" way to bypass a circuit breaker for testing is to get a fuse the same amperage and tack that in parallel with the open breaker....Of course if there's a fault causing the tripping you'll waste fuses trying to troubleshoot it.

[vortalexfan]

Originally Posted by Electronic M

One "safe" way to bypass a circuit breaker for testing is to get a fuse the same amperage and tack that in parallel with the open breaker....Of course if there's a fault causing the tripping you'll waste fuses trying to troubleshoot it.

Well I'm pretty sure its not a fault in the circuitry because the breaker will "trip" without me even having the TV plugged in and powered on, all I'm doing is moving the TV from laying on the TV screen (face down) to moving it into the upright position (the TV screen facing the wall and the bottom of the chassis facing the floor) and after I do that I plug the TV in and go to power it on and the TV is dead and I unplug the TV and flip it back onto its face and check the breaker and sure enough its "tripped" (it doesn't beep with the continuity test on my DMM) and the only way to "reset" the breaker is to use a screwdriver because the red reset button doesn't doesn't do anything to reset the breaker element for some reason.

Also when I looked at the breaker it doesn't look like its original because there's a blob of solder on the chassis of the TV under the circuit breaker and a little blob of solder on the bottom of the circuit breaker itself but the solder blobs don't match up (almost like the circuit breaker was taken from another TV and installed inside this one to replace the original circuit breaker.)

[vortalexfan]

OK, I found a proper replacement circuit breaker for my TV. It was $5.50 plus $4.50 shipping.

Its a GC Electronics NOS Exact Replacement 2.75 Amp Circuit Breaker, which is what the breaker that came out of it was rated at (it was a Zenith replacement part because the part number on the breaker in this unit was the same as the one listed in the Sam's Service Info), like I said I don't think the breaker in this TV is the original breaker because like I said it shows evidence of being replaced at one point in time because the solder blob at the bottom of the circuit breaker that would hold it to the chassis (or possibly ground the breaker to the chassis) was disturbed and wasn't re-flowed.

[vortalexfan]

OK, so a little update, I did manage to repair the circuit breaker, and I did get the TV to produce a full screen raster, but I'm not getting anything out of the tuner (no snow or white noise just a blank raster), and I think it might be because the tuner has some dead tubes in it, because when I looked at the tuner I only saw one of the tube glowing in the VHF tuner and the UHF tuner tube isn't glowing either.

See picture below to see what the TV looks like currently.

[init4fun]

Originally Posted by vortalexfan

Ok, take at easy dude, I was asking because I thought you were suggesting that I was going to find them brand new somewhere which I wasn't sure how that was going to be possible seeing as TVs haven't had circuit breakers in them like that since the 1980s, I didn't realize you meant going to ebay and finding a NOS circuit breaker.

This is the first TV I've worked on that had a circuit breaker on it so I didn't know... 😶

Well I'm happy to hear you've got it working, without any of that nasty "bypass" business

[Notimetolooz]

That neon bulb is connected between the horizontal section and the CRT.
I think it passes pulses from the horizontal output transformer to the grid to blank the CRT during the horizontal re-trace. You might not even notice if it was not working, many earlier sets did not bother with horizontal blanking because the beam travels so fast it doesn't light the phosphor much.

[old_tv_nut]

In early sets with full DC response, the retrace would normally be at or below black (with the correct brightness control setting). When sets were designed with less or no DC coupling/restoration, V and H blanking was needed to prevent retrace visibility on dark scenes. Later, with color broadcasts, the color burst could become visible in the retrace if there was no H retrace blanking.

[consoleguy67]

Go with your gut, and check the tubes in the tuner first.

[zeno]

Run the set a few mn & see if the tubes get hot. Its pretty
rare on a parallel filament set to get an open tube never mind
two of them.

Next run set. Change channels. You should see & hear a lot of noise
from the switches making & braking.
If you dont its father down the line, prob one of the IF tubes.

73 Zeno
LFOD !

[vortalexfan]

Well I put the set back together ran it for a little bit and all I'm getting through the speaker is a very pronounced "vertical Oscillator" noise through the speaker and some very faint white noise coming through the speaker, I have a converter box hooked up to the set and and I was going through all of the channels and I wasn't getting any signal through whatsoever, not even the backlight bulbs for the tuner are working but yet the motorized tuning is working (you push the button on the front panel of the TV and the tuner advances through the channels as it should) but since the pilot lights aren't working I can't see what channel I'm on.

Also as far as the picture goes, I can't tell if the vertical and horizontal hold are adjusted correctly because I can't see the lines from them on the screen because its just a bright grey color and you can't see any snow or anything on the screen..

[Electronic M]

This era of Zenith used a barrel connector for tuner B+ and 2 identical spade connectors (aside from wire color) for AGC and tuner heater. If neither of the tuner tubes or tuner bulb lights you may have the tuner and AGC spade connectors on the tuner mixed up. I made that mistake in the last month and it didn't damage anything.

[vortalexfan]

Originally Posted by Electronic M

This era of Zenith used a barrel connector for tuner B+ and 2 identical spade connectors (aside from wire color) for AGC and tuner heater. If neither of the tuner tubes or tuner bulb lights you may have the tuner and AGC spade connectors on the tuner mixed up. I made that mistake in the last month and it didn't damage anything.

I'm thinking that might be part of my problem. Do you have a diagram or a picture showing which wires go where when it comes to the heater and AGC wires for the tuner?

Also another issue I noticed with this TV's tuner was that the section of the terminal strip where the B+ connector goes to was broken so the terminal is just floating in mid air, and only being held into place by the 3 large resistors soldered to it.

Also is the motorized tuning portion of the tuner affected by the 3 tuner connectors or is that independent of that?