Quote:
Originally Posted by Kamakiri
I get where you're going here. I was going to ask, then why does the set have a full raster on blank channels, but as I'm understanding this, there wouldn't be, because there is no signal for the syncro-guide circuit to do anything *with*. Since there is a full raster off-channel, I'm not dealing with a deflection or HV issue, that would be the wrong circuit to even think about. Am I on track here?
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Yes! And also why adjusting your AGC shifted this!
Many newbies mistake this for image bloom from high voltage issues and it is kinda hard to locate the trouble when looking in the wrong place.
Quote:
Originally Posted by Kamakiri
Should I do any further component checks (as in resistors, etc), before I begin eyeballing the setup? The set has about 8 hours run time on it since the re-cap, I just don't want to let any "bugs" it may have do any damage.
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As you just said, check all your tubes, but remember, the final check on a tube without any shorts is how well it works in the circuit. Actually, I usually check tubes, especially for shorts, before the first power-up, to lessen chances of frying a newly installed part.
This would be a good flow plan to complete the electrical work:
1) Check the 39 & 47 ohm resistors from the cathode of the 6BG6 to the -120v source.
(Not related to the problem at the moment, but also check to see if the fuse in the damper circuit is the correct value. I've seen some of these increased in value by servicemen to prevent callbacks as the sets got older.)
2) Find a slug that fits the horizontal linearity coil and then adjust the horizontal linearity. (Sams # L42 and Adjustment B4) Use your DVD alignment pattern for this. If your linearity does not change, your coil may be shorted, or there may be a wiring error from recapping. The set should be in its working position (not on the side) when making the final linearity adjustment.
If you think the used core you are testing makes too much change, try a smaller core.
3) At this point get yourself a red grease pencil and mark the Sams "B" numbers on the correct parts, so you won't accidentally align the wrong part. (Don't ask me how I know this is important.
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4) If the image looks reasonably OK and only a minimum of overscan, follow the Sams page 7 for setting the AGC Threshold, but do it visually for cleanest picture (ie, back off to just before overload) for now.
5) Follow the Sams page 18 synchro-guide instructions in order, except for checking the waveform. Since you have no scope, yet, you will judge the correct position of B6 by the most stable lock-in range.
6) After finishing step 5, set the set aside for now. If it is behaving better, it is OK to temporarily slide it in the cabinet watch it, since a little running time might help to drive out any remaining moisture.
7) When you get the scope working and you have either built a low capacity probe or confirmed that yours is not leaking, check the B6 adjustment again and if it is out, correct, and let us know what you found.
After correcting the wave form, you probably will have to re-tweak some of the other adjustments.
James.