27" Panasonic blank-out


  #1  
Old 06-05-02, 09:14 PM
SeanV
Visiting Guest
Posts: n/a
Unhappy 27" Panasonic blank-out

Hello!

We've had a Panasonic Ct-27D10B for almost two years now and just recently the picture has been switching back and forth between good and too dark -- all by itself. Additionally, sometimes the picture goes black completely. (There is still sound coming through the speakers, though.) We have found that if we turn it off, and back on again, it will work again for awhile.

This happens regardless of the video input mode: component, video line, etc.

Any ideas? Will this be $$$ to fix?

Thanx!


-SeanV
 
  #2  
Old 06-06-02, 07:34 AM
Smokey
Visiting Guest
Posts: n/a
Thumbs up

Good Morning, SeanV:

A lot of these "higher end" Japanese sets have a circuit to change the brightness of the picture in relation to the light in the room. Most of the circuits are more a pain than anything else.

Access your menu and see if there isn't a light sensor in the set.
If there is, then simply turn it off.

Second thought is filaments on the picture tube. Watch the glow of the filaments on the tube through the back and see if there is any difference when the tube starts to get darker. A cold or high resistance solder joint may be robbing the picture tube filaments of enough power to cause this problem.

If this doesn't work, come back and we'll talk about electronic circuitry repairs, etc.


Smokey
 

Last edited by Smokey; 06-06-02 at 12:23 PM.
  #3  
Old 06-07-02, 09:21 AM
SeanV
Visiting Guest
Posts: n/a
Thanx for the info Smokey, unfortunately I don't think our TV has one of those light sensors. (I checked the front of the set as well as the menu options, and there was nothing but the infrared sensor.)

What is it I should look for next? Something about a light or something inside the cabinet...? I didn't quite get that.

-SeanV
 
  #4  
Old 06-07-02, 07:40 PM
Smokey
Visiting Guest
Posts: n/a
As I said on the previous post, the next thing is to check the filaments on the picture tube. Is the "glow" the same as it is at high brilliance pictures as it is when the "picture goes dim"?

Bad solder connections! These are bane of Japanese sets and are a constant problem. So, we look for a bad filament connection, then we check the boards for a bad video connection, etc.

We take off the back of the set and tap around with a non-metallic probe to "jar" things a bit. Can we change the picture on the screen from our probing? If it is "Yes", then we deal with bad solder connections.
This means a little 60-40 electronic solder, a low heat soldering iron, and a little patience.

Are you up to this? Or are you ready to call the technician?
We're ready to deal with it either way.

Smokey
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: