Quote:
Originally Posted by Espo
Thanks for the quick responses. There are two mica caps that I see in the sync separator circuit. They are C145 and C147. These are 270 uF mica caps between V118 the first sync amplifier and V119, the sync separator. I didn't change those, because I thought doing so would then require me to perform a full alignment which is out of my comfort zone. Are those two possible culprits? If so, I'll get rid of them.
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First thing is first, make sure you can get correct contrast.
The sync separator depends on video amplitude being within a correct range. If the video level is too low or too high then even a properly operational sync separator will not provide the right output (garbage in garbage out).
The sync separator has no relation to alignment. (And if you chopped off all the IF systems and injected audio and video you would still need the sync separator stage to allow H and V to sync.)
If the video level into the synch sep is correct per-original design, then yes those capacitors could be a problem...As could any resistors in the circuit or the tube.
General roll troubleshooting advice: in a set where all else works correctly if both H and V roll (and user controls allow you to adjust which direction it rolls) then the issue is almost always in the sync sep stage.
If only one axis rolls (direction controllable) then the issue is probably in the axis rolling though could be a separator issue if the other axis has weak sync with a very small lock in range. If contrast is excessive or insufficient at normal screen brightness (assuming good CRT) and both axes roll the problem is likely to be video level. If an axis rolls, but you can only get it to roll one way that axis has problems/is operating off frequency. If only one axis rolls (other has a solid lock) then that axis or it's connection to the sync sep is at fault.
This is a case where it is best to find the problem through diagnostics rather than throw parts at the wall to see if they stick.