Motorola 19k14wa Possible Arcing?

[mr_rye89]

Well the sync went funny again. So I pulled the board and found a crack in the ground plane trace around the edge of the board (near the horizontal output tube - high stress area), solder bridged it back and got sync again

The sync circuit must have been dropping the ground there intermittently.

Now the horizontal linearity is a bit off, but I screwed up the noise gate (sync stability) pot so now to fix that.....

[dieseljeep]

Originally Posted by mr_rye89

Well the sync went funny again. So I pulled the board and found a crack in the ground plane trace around the edge of the board (near the horizontal output tube - high stress area), solder bridged it back and got sync again

The sync circuit must have been dropping the ground there intermittently.

Now the horizontal linearity is a bit off, but I screwed up the noise gate (sync stability) pot so now to fix that.....

That PC board job wasn't one of Motorola's better efforts. They made a few years of those and then went back to the hand wired chassis. The tuners were also trouble prone. Yours is probably the last year of that chassis.

[mr_rye89]

This ol' ball of wax again.

I'm having problems with the horizontal, barely able to hold a steady picture, and I have determined the voltage is too low on the horizontal oscillator tube due to out of spec resistors in the horizontal sweep couplate. I have built simple couplates in the past using perf board, but these are some stacked up monstrosities with 12 pins. Anybody here attempt to make one of these? I'll likely try to build the new ones similar to how the old ones are made.....

[maxhifi]

Originally Posted by mr_rye89

This ol' ball of wax again.

I'm having problems with the horizontal, barely able to hold a steady picture, and I have determined the voltage is too low on the horizontal oscillator tube due to out of spec resistors in the horizontal sweep couplate. I have built simple couplates in the past using perf board, but these are some stacked up monstrosities with 12 pins. Anybody here attempt to make one of these? I'll likely try to build the new ones similar to how the old ones are made.....

Have you attempted to replace the horizontal phase detector diodes? Those are easier to change, and could possibly also cause this issue. It looks original in that photo.

[Electronic M]

Originally Posted by maxhifi

have you attempted to replace the horizontal phase detector diodes? Those are easier to change, and could possibly also cause this issue. It looks original in that photo.

+1.

[old_coot88]

Definitely replace the dual diode if you got horz sync issues that subbing the tube don't fix.

[mr_rye89]

Would silicon rectifier diodes work there? I have some of those laying around......