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.

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.

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.

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 !

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"?

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 !

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).

Perhaps the vacation switch would turn off the remote receiver?

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 !

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.

... 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.

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 !

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.

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!

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

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

Well I looked at the CRT Socket board and I think I figured out part of the reason why this TV isn't working right, the CRT Socket Board was broken in half at one point in time in the TV's history and then was glued back together and the broken traces bridged with wire.

So then the 3 Variable Rheostats on the CRT Socket board marked as the Red, Green and Blue Screen Adjustments are the G2 adjustments on this TV?

Yes they are the G-2 controls. Watch the crack, it may have traveled....

Zeno

G2 = "screen grid." Although it's in the same order of electrodes as a screen grid (second grid) in a small signal tube, it doesn't perform the same function (screening the control grid [grid 1] from capacitive coupling to the plate) in a CRT. Instead, it is used for setting the cutoff point of voltage between the cathode and G1.

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

Well I turned them up and all I get is the green, the red is pretty much dead, and the blue is pretty much dead, they barely show up on the screen, the green however is fine, and thats with the blue and red adjustments on the back turned all the way up... :scratch2: