[Kaptah]

Hi,


my old and faithful Sony 1270 broke yesterday after 11 years of service. I would appreciate any feedback on the possible problem location. I'm going to repair it myself, just got the schematics.


The problem description is as follows:


1. After an hour of watching, the video suddenly disappeared from the blue tube. Red and green pictures are ok.


2. The blue tube is still evenly emitting light stably. The brightness is perhaps 10% of full brightness, so the light intensity is now bigger than usually with no picture.


3. There is no any kind of picture coming through the blue tube:

- No composite video.

- No VGA video.

- No internal projector control graphics.

- No "service man" test mode graphics (zone settings etc).


4. Remote control blue Bias and Gain controls do not effect the blue tube light intensity.


Could someone please comment on the possible location of the broken component? Which PCB board is the most probable culprit? There are so many PCB boards in difficult locations...


I wonder if it is a broken power transistor, capacitor, resistor or diode?


Thank you!

 

[Prehjan]

This is a job for Curt ...chances are you blew something on the boards!


I would send them to Curt to figure out/repair.


My guess would be the neck board! ...or something totally unrelated to the chain!


Martin

 

[sycho]

It looks like you have bad CA(B) board. I had same problem on my 1270 except it was on Green. It was bad CA(RG) board. I replaced with good one and it works fine now. Hope this helps.