Zenith 25LC20 chassis alignment.....HELP! :(

[nasadowsk]

Ok, ok, I've got my 25LC20 mostly there, but it's just not exactly where it should be. *every* adjustment on this thing was messed with, and it took three passes through the procedure to get it to this point.

My big trouble seems to be I still can't get the bandwidth I need. Taken from point C1:

Picture 1 is the 41.75 marker. It should be about 35% up the slope. I can't get it there, period.

Picture 2 is the 42.75 marker. This doesn't look too bad.

Picture 3 is the 45.00 marker. It's not too bad either.

Picture 4 is the 45.75 marker. It's not 50% up the slope like it should be, but it's not as bad as the 41.75.

I've done the Zenith book procedure on T4 and L10, etc, fed into the 3rd IF grid. That seems to be darn near perfect. The only glitch is the null pot seems to affect the entire curve, not just the tunned spot at 41.25.

I'm not sure where to look, now. Tubes? AFAIK, they're all original to the set. Could I have a bad cap or resistor in there? Am I screwing everything up by putting the setup switch on (to kill the vert) and pulling the horizontal tubes? Am I trying to get something that Zenith says I should be able to get, but in reality, can't? The set gets a pretty decent B&W picture now, but I can't get the color to work at all (another headache, I'm sure), and I'm wondering if the alignment results I have now will even pass color (once I get that sorted out).

One other thing: The picture detector was shorted when I got the set. I put a 1N34 in there. Is that a good sub, or is that potentially messing me up?

Thanks!