J
JURB6006
Guest
Hi;
AP63 chassis lives there for those of you who now remember chassis numbers.
This one has lines. They are wider spaced and curved toward the top and finer
and diagonal at the bottom. This is accompanied by a buzz in the audio at the
frame rate. Power supply right ?
Checked all the filters and replaced about 10 marginal ones. Checked filters
around the regulators on the signal board as well, got about 3 of those. No
change.
The set came in running, I'm told that this just happened, both symptoms at
once. I wasn't finding any significant ripple on any of the supplies, and all
the caps I changed were only marginal, not real bad.
Since this path seemed to go nowhere, I decided to attack from a different
front. The sound is showing an RF envelope like, modulated at the vertical
rate. Then I hit ground in the audio and found the same signal, at about a volt
peak to peak !. This is from ground to ground !
This is infecting the video AND the sound, but it does not cause any horizontal
jitter so it must be after sync. Also, the effect appears in the onscreen
display.
There is no jitter, no size variations, no geometry problems. Convergence is
decent.
Any ideas ? thanks for your time.
JURB
AP63 chassis lives there for those of you who now remember chassis numbers.
This one has lines. They are wider spaced and curved toward the top and finer
and diagonal at the bottom. This is accompanied by a buzz in the audio at the
frame rate. Power supply right ?
Checked all the filters and replaced about 10 marginal ones. Checked filters
around the regulators on the signal board as well, got about 3 of those. No
change.
The set came in running, I'm told that this just happened, both symptoms at
once. I wasn't finding any significant ripple on any of the supplies, and all
the caps I changed were only marginal, not real bad.
Since this path seemed to go nowhere, I decided to attack from a different
front. The sound is showing an RF envelope like, modulated at the vertical
rate. Then I hit ground in the audio and found the same signal, at about a volt
peak to peak !. This is from ground to ground !
This is infecting the video AND the sound, but it does not cause any horizontal
jitter so it must be after sync. Also, the effect appears in the onscreen
display.
There is no jitter, no size variations, no geometry problems. Convergence is
decent.
Any ideas ? thanks for your time.
JURB