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-   -   1970s J. C. Penney 19" Color TV issues (http://www.videokarma.org/showthread.php?t=272280)

vortalexfan 11-19-2019 09:26 PM

1970s J. C. Penney 19" Color TV issues
 
2 Attachment(s)
Hello everyone, earlier today I had picked up from a local electronics recycling facility/computer store a 1970s vintage solid state J. C. Penney 19" Portable Color TV that when I got it home to try it out everything on it except the picture worked on it, it has audio and the channel selector lights work and everything.

When I turn on or off the TV I see the colors wash across the screen like it was showing some sort of picture but when the set is actually one or powered on the screen is completely blank, no snow or anything.

Any ideas as to what could be wrong with this TV?

Also who made this TV for J. C. Penney? It says Made in Japan on the back of the set.

Pictures of the set in question posted below.

Electronic M 11-19-2019 09:33 PM

Odds are it is missing G2 voltage or one of the other elements common to all 3 guns is not getting power.

Time to check voltages against CRT datasheet or schematic.

vortalexfan 11-19-2019 09:38 PM

Quote:

Originally Posted by Electronic M (Post 3217857)
Odds are it is missing G2 voltage or one of the other elements common to all 3 guns is not getting power.

Time to check voltages against CRT datasheet or schematic.

It does have a service switch on the back which I can't tell if its in the normal position or if its in the service position.

Also I don't know who made this set for J. C. Penney or what the model number is so I'm not sure if I'll be able to find any service data on this set.

zeno 11-20-2019 07:07 AM

The set is a Panasonic.
If you have audio ( hiss) but a total black pix you have a video
problem. Try cleaning the service switch, I thing it has one.
Also try turning up the G-2 a little. After that it gets "interesting".
Post a few chassis pixs also.

73 Zeno:smoke:
LFOD !

vortalexfan 11-20-2019 07:15 AM

Quote:

Originally Posted by zeno (Post 3217866)
The set is a Panasonic.
If you have audio ( hiss) but a total black pix you have a video
problem. Try cleaning the service switch, I thing it has one.
Also try turning up the G-2 a little. After that it gets "interesting".
Post a few chassis pixs also.

73 Zeno:smoke:

LFOD !

Yes it does have a service switch, but it's only accessible with the back cover off oddly enough (it only has a small slit in the cover for it).

Is this a fairly early solid state set like my Sylvania is?

And what do you mean by it gets "interesting"?

zeno 11-21-2019 08:29 AM

The set has no crazy circuit designs so easy to deal with. You may need
a manual, what is the model number ?
Most likely set has low G-1. Normally it adjusts from abt 200-800 VDC
with abt 400 V for a normal picture.

73 Zeno:smoke:
LFOD !

vortalexfan 12-08-2019 11:28 PM

6 Attachment(s)
OK So I finally was able to get my workshop put back together after it being torn apart for almost half a year because of mold problems due to water infiltration through the foundation of my side of the house (the part of the house where I live in/use used to be an old detached garage that the previous owners of the house had built in and made part of the house, but never properly sealed the foundation or the cement slab from the garage).

Anyways I finally got this set torn apart and I found a few curiosities in this set, it seems this set may have had an ultrasonic remote control unit for changing the channels as I saw what appeared to be a motor attached to the tuner assembly that is geared so that it can control both the UHF and VHF tuners, and the TV also has a vacation switch on it which I thought that was something that was more on Tube Powered TV Sets and not Solid State Units?

Another interesting thing is that this unit is completely modular, as in it has removable/replacable modules for making this set work, another interesting thing is that the Audio section of this TV in spite of it being all solid state uses an audio output transformer for the speaker (which leads me to think this TV might actually be late 1960s or very early 1970s).

Its also very filthy inside the set, also I can't seem to find the G2 control in this TV.

Pictures of the inside of this TV posted below (finally).

MadMan 12-09-2019 02:47 AM

Perhaps the vacation switch would turn off the remote receiver?

zeno 12-09-2019 08:05 AM

One of these ! Very nice set. Its a delta tube so has 3) G-2
controls one for each color. Not sure but it may have separate
outputs for hoz sweep & HV. Do you have HV ?? Also find
that model number & it may have a chassis number on a white tag.

73 Zeno:smoke:
LFOD !

vortalexfan 12-09-2019 08:40 AM

Quote:

Originally Posted by zeno (Post 3218580)
One of these ! Very nice set. Its a delta tube so has 3) G-2
controls one for each color. Not sure but it may have separate
outputs for hoz sweep & HV. Do you have HV ?? Also find
that model number & it may have a chassis number on a white tag.

73 Zeno:smoke:
LFOD !

Ok, will take a look.

old_tv_nut 12-09-2019 09:35 AM

Quote:

Originally Posted by zeno (Post 3218580)
... Not sure but it may have separate
outputs for hoz sweep & HV. ...
73 Zeno:smoke:
LFOD !

Interesting - first I've heard of a consumer set with separate H sweep and high voltage. Only ones I ever saw were broadcast monitors, with both sweep and HV regulated individually so no size modulation with brightness.

zeno 12-09-2019 10:57 AM

Quote:

Originally Posted by old_tv_nut (Post 3218587)
Interesting - first I've heard of a consumer set with separate H sweep and high voltage. Only ones I ever saw were broadcast monitors, with both sweep and HV regulated individually so no size modulation with brightness.

Sony did it before the SG613 sets. Panasonic & I think a few more
also did. Very short lived design from the early 70's but it did work good.

73 Zeno:smoke:
LFOD !

vortalexfan 12-09-2019 06:05 PM

1 Attachment(s)
Quote:

Originally Posted by zeno (Post 3218580)
One of these ! Very nice set. Its a delta tube so has 3) G-2
controls one for each color. Not sure but it may have separate
outputs for hoz sweep & HV. Do you have HV ?? Also find
that model number & it may have a chassis number on a white tag.

73 Zeno:smoke:
LFOD !

OK I think I found the chassis number tag and also the model number as well, both on a small white tag affixed to the chassis frame.
See picture below for the tag in question.

old_tv_nut 12-10-2019 11:42 AM

Quote:

Originally Posted by zeno (Post 3218595)
Sony did it before the SG613 sets. Panasonic & I think a few more
also did. Very short lived design from the early 70's but it did work good.

73 Zeno:smoke:
LFOD !

thanks for the info!

zeno 12-10-2019 03:33 PM

The set is covered in Sams 1472-1
Measure the CRT pins 2, 6, 11, 4, 5, & 13 for VDC.
Be sure your meter goes to at least 800V.

Next the 3 G-2 controls are on the CRT socket. Turn
one up all the way & see what you get on the screen.
Then put it back & report findings.

Zeno


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