Quote:
Originally Posted by rca2000
CTC-101. Pretty sure it is NOT a modular set.. Hot chassis, SCR reg..
Going "all white with retrace"...sounds like you may be losing the video bias supply--intermittently. This is what is often called the "200 volt line", or such. It usually comes from the flyback. THINK...there MAY be a small choke or two...that intermittently opens..allowing the three video drivers ALL to 'float towards ground."..and then the raster will go white w/retrace and in many sets...shut down.
ALso...there should be a "luminance buffer or driver" transistor, somewhere on the chassis...and if it goes leaky or shorts...the result will be similar.
DO NOT believe this is a CRT issue--since all 3 guns are doing this . If it was the tube..ONE color would be going full-on, if a cathode was going shorted(or socket on CRT.)
|
rca2000, thanks for the reply and insight! I will investigate.
This set is somewhat modular- remote, tuner and stereo sound processor plug into chassis. I will check the schematic for inductors/choke off the flyback.
I am suspecting something in the luminance circuit. It has a Luminance Processor IC - from that there is a the following transistors: Contrast buffer, 2nd video, black clamp and video buffer. It could be the Luminance Processor IC or the video buffer transistor.
I agree with your assessment on the CRT.