63 silvertone roundie - Videokarma.org TV - Video

timmy · #1 07-13-2012, 11:41 AM

hey all, this set developed rgb retrace lines from top to bottom they are faint but i can see them which were never there. crt bias counter clockwise and the rgb drives are low. any quick fix that anyone may have an idea befor i go full blast into this set to look?

ctc17 · #2 07-13-2012, 12:22 PM

The color is working right otherwise? Do they go away if you turn the color all the way down?

timmy · #3 07-13-2012, 12:41 PM

color down they are still there, otherwise its working great.

marty59 · #4 07-13-2012, 01:14 PM

Are they only visible in "low light" or "high light" areas of the video? Or all the time?

timmy · #5 07-13-2012, 02:33 PM

high lights in the video it can be seen.

wa2ise · #6 07-13-2012, 03:24 PM

Most TV sets use a pulse from the vertical output to drive a grid in the CRT to make the CRT cut off. If the set sends the video to the cathode, as most do. Bad capacitor?

Are you trying to watch a DVD or tape with Macrovision pulses in the vertical interval. These come and go every minute or so.

*zenithfan1* · #7 07-13-2012, 03:25 PM

Have you checked the video output tube for shorts? It's probably a 12BY7 if it's an 11 or 12 clone. When mine developed a short the exact symptom you described showed up.

timmy · #8 07-13-2012, 03:51 PM

no dvds just tv. a cap, in the vert board?

ctc17 · #9 07-13-2012, 04:43 PM

red green and blue bars running up and down?
That is one I have never seen. Almost sounds like some low level ripple getting into the chroma board. Maybe a heater to cathode leak in one of the 6GU7s or other tubes in that area? Weak filter? Video tube with some weird condition like mentioned.

I would start pulling the tubes behind the 6GU7s out one at a time with the color off and see if it you can get it to go away.

timmy · #10 07-13-2012, 04:51 PM

the 3 color lines are left to right but each section of bars start on top and kind of fade toward the bottom.

mstaton · #11 07-13-2012, 05:46 PM

Can you post a picture? It would be most helpful.

timmy · #12 07-13-2012, 05:55 PM

probably not be able to see them as they are very light.

marty59 · #13 07-14-2012, 04:10 PM

I'd also look at voltages around the video output as well as making sure the service/normal switch is good and follow out to the drives and do some resistance checks/troubleshooting in that area. Do brightness and contrast work normal and is there any effect on your symptom?