Sony Trinitron picture flickers off and on
 

I have a Sony 35/36 inch Sony Trinitron TV made circa 1999. The picture keeps blinking off and on and I'm just wondering what it could be. It was given to us by my aunt. The model number is KV-35V42

The picture is flashing as a result of the AKB circuit trying to adjust for the correct bias to the CRT; but, it can't because one (or more) of the CRT guns has become too weak. In the early stages, it may be possible to tweak the master G2 control to stop the blinking video; but, the problem will only get worse as the tube further weakens. Other options are to add a CRT brightener (the newer type for flyback powered filaments) or rejuvenate the CRT. The brightener will also only be a temporary fix and Sony CRT's often don't last very long after rejuvenation. They look good at first and then they fall off, and often look worse, after a short time.

Seems to me that a bad regulator IC caused a problem like that also, causing the sweep and HV to jump up and down. I'd check the HV and regulator voltages before declaring the CRT bad.

Thanks all. Mom called a TV repairman and he says the tube is going and in fact the blue gun is so weak, the picture has a greenish hue to it. It could be on its way out unless someone has any suggestions or ideas.

From what you say about the picture, it's certainly the tube. You could try the suggestions I mentioned above to squeeze a little more life out of it; but, unless you can find a good tube, this set is/will soon be dumpster material.

Definitely if your description is accurate, it's a weak CRT. You might be able to buy a few months by backing down the G2 control just a hair, but you need to be planning on another set, or if you want to keep that one, find another set with that tube and swap it.

If the set happens to be a 1989-90 KV-32SXR10, it could be a bad solder connection at the delay line on the video board, but that's ONLY on that model. And the greenish hue IS the CRT, even if the flickering isn't .

Charles

Hey Charles, you helped me with my 27" EXR set several years ago having this same problem with the blinking CRT, and helped me cross-reference a replacement tube that I had on hand. Long story short, it's still working perfectly today.