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-   -   1976 RCA picture problem (http://www.videokarma.org/showthread.php?t=271080)

Jeff-20 11-17-2018 01:14 AM

1976 RCA picture problem
 
1 Attachment(s)
Anyone here want to take a shot at diagnosing a picture problem?

RCA solid state 17 inch black and white. Sound is ok. Picture seems small. Channel tuner seems very fickle.

kf4rca 11-17-2018 07:36 AM

Low voltage from power supply.

zeno 11-17-2018 07:53 AM

Tuner probably just needs cleaning.
Size problem probably power supply.
Post the CHASSIS number from inside its like KCS###
and maybe we can give some hints.

73 Zeno:smoke:
LFOD !

Jeff-20 11-17-2018 03:29 PM

Inside it reads:
KCS202R
RWZ Li
2747622-0(?)
REV 005

I can remove the tuner, but I am not sure what to do with it.

zeno 11-17-2018 04:04 PM

OK I pulled the manual & its a simple set to deal with.:banana:
For the others its the B&W chassis with modules. A common & good set.
Before we go any further need to know what experience you have.
Also if you have a meter. You WILL need a meter for the size problem.
Let me look on Utube for a tuner cleaning video. You can use
WD40 but its best to use very little & put it in the best places........

73 Zeno:smoke:
LFOD !

Eric H 11-17-2018 06:29 PM

Are you sure the size issue isn't the source (Video Game?) feeding it a cropped image? If you put it on a blank channel does the screen fill out?

Jeff-20 11-18-2018 01:24 AM

4 Attachment(s)
THanks, everyone. I am consolidating responses from two different threads.

Quote:

Originally Posted by dishdude (Post 3205845)
The picture looks pretty darn good. How do you have the game console connected to the set? Lets see some more pics.

Yes, I can no longer get analog stations, so I connected an Atari VCS to the antenna screws via an Atari RF switch box.

Quote:

Originally Posted by dieseljeep (Post 3205847)
Picture looks pretty darn snowy! Try wiggling the selector knob. If it gets clearer, clean the tuner. If not, look at the connections to the antenna.
The reduced display size looks like the source is producing it!
A power supply problem would produce some distortion in the display, IE ripples.

The image is usually distorted when I first turn it on. I have to nudge or wiggle the channel knob a bit before the image comes in with snow. (pics below)

Quote:

Originally Posted by Eric H (Post 3205856)
Are you sure the size issue isn't the source (Video Game?) feeding it a cropped image? If you put it on a blank channel does the screen fill out?


Quote:

Originally Posted by diesel
Are you trying to run it with some kind of a TV game? I don't remember if that model has a coax input. Try it with a DTV convertor instead.

I bought and connected a digital tuner, and the image was still small (pic below).

Quote:

Originally Posted by zeno (Post 3205852)
OK I pulled the manual & its a simple set to deal with.:banana:
For the others its the B&W chassis with modules. A common & good set.
Before we go any further need to know what experience you have.
Also if you have a meter. You WILL need a meter for the size problem.
Let me look on Utube for a tuner cleaning video. You can use
WD40 but its best to use very little & put it in the best places........

Yes, please. I bought a meter (pic below), but I am new to using them. I've poked around arcade crt monitors, but I would need guidance.

kf4rca 11-18-2018 07:23 AM

I thought it was an LPTV you were tuned to. There's an LPTV in this market that looks like that (very snowy). There are still a few analog signals on the air.

zeno 11-18-2018 08:31 AM

Look around the main PCB for a crack. Especially where it is soldered
to the main frame. IIRC I had a few of the similar 12" sets with
cracks. Also be sure the modules are seated. Almost has to be moving
damage.

73 Zeno:smoke:
LFOD !

Electronic M 11-18-2018 10:13 AM

My thoughts based on the recent pics:

Seller pic shows some snow. The tuner was probably dirty then and has gotten worse.

Your snow picture shows that the raster almost completely fills the screen which points to two things: the small bit of wavy underscan on the side is probably one or more power supply lytics failing. And all your current signal sources are cropping the image...Your DTV box should have crop/zoom settings try playing with them...Also try different channels as some channels lock the zoom/crop settings such that a box can't fix it.

One more thought there is an analog channel 6 in the Chicago market (they are pretending to be an FM radio station, but have to keep their video carrier on to send audio) you may want to try tuning them.

Eric H 11-18-2018 01:08 PM

Didn't know you had it shipped, check to see if the Yoke has slid back on the neck of the CRT.

The pictures is small but perfect, bad power supply will usually have some other symptoms.

dishdude 11-18-2018 01:21 PM

Get rid of that Atari switch box, they were garbage when they were new.

Jeff-20 11-18-2018 04:06 PM

5 Attachment(s)
As always, I have to jiggle the tuner a bit to get a signal. I was able to tune in channel 6. It was on 7 at first, so I had to fine tune for a bit. I get clear audio but no video, but this is the same on my working tvs.

I am including more interior images (excuse the quality). I can include links to youtube video if helpful.

Jeff-20 11-18-2018 04:10 PM

3 Attachment(s)
... It's also worth noting that when it arrived, the lower left part of the screen was pushed into the frame. I snapped back pretty easily, but could be relevant. I'm including images of the packaging as well.

Eric H 11-18-2018 04:44 PM

Loosen the yoke clamp and make sure it's pushed all the way up against the back of the tube. It looks okay but obviously the set took a hard hit if the tube was dislodged.


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