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#1
10-20-2010, 05:52 PM
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The Dick Van Dyke show always looks better on a real B/W TV!
You are down to the finish line, now. It's really looking good! Bruce 
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#2
10-20-2010, 06:56 PM
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Good eye, Bruce! I had Dick Van Dyke playing on the DVD player. I have this set I bought at Wal-Mart with 65 hours of old tv shows. I think this episode was about an italian guy painting their living room.
Yeah, I'm not sure about the contrast. I think I've cancelled out the chance of any bad tubes, unless 1B3 tubes get weak and cause poor contrast somehow? I don't think that would happen, but it was mentioned in one of those repair books I've got. I have a picture of my contrast/video section. I had a hard time matching some of these weird components to the schematic:  Wow, my labeling didn't work out so good. Anyways, there's some capacitors listed that I couldn't find, as I recall. Those little cylinder/disk things around the sound take-off coil looked like tiny resistors or something, and I'm not sure about that green thing that's marked with paint dots like an old resistor. There's a similar one that's red like this and where I'm looking on the schematic, it mentions a capacitor. I wasn't sure if these were were caps, or resistors. The peaking coil, that someone had suggested might be open, appears to be that "blob." Looks like a resistor with a coil around it, coated in wax. Am I right? It said 10 ohm on the schematic and this measured 8 ohm on my multimeter. I've been meaning to apply that video signal to see if the problem is before or after the video amp, but I don't seen to have any spare .1 capacitors to protect my DVD player. Last edited by RitchieMars; 10-20-2010 at 07:03 PM.
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#3
10-20-2010, 07:20 PM
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ID peaking coil Correct!
Green cap with the yellow/purple/black dots = 47 uuf shown across sound takeoff xfmr ... 22k resistor just below the green cap. Little disk circled is likely the 3.3 uuf cap on the sound takeoff xfmr. jr
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#4
10-20-2010, 07:29 PM
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Wow, so those are capacitors... weird. Are these considered ceramic or wax, or what? I've never seen much information about these. Reliable? I know they're small values, but they are right there around the contrast control, namely that C32. It's hard to believe that such small caps could cause my contrast to work the way it is, but who knows. Also, my set doesn't have a screen register control on the front, so I'm guessing that R25 would be a fixed resistor in this case rather than a pot. I'm not sure if the screen register has much bearing on contrast, though.
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#6
10-20-2010, 11:00 PM
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Quote:
__________________
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#7
10-21-2010, 07:22 AM
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Well, that sound coming from the HV cage could be causing your problems. Maybe not a failing flyback, but rotting wires, etc could be discharging some of the HV before it gets to the picture tube. My CTC-9 had lousy HV until I listened in and heard a hiss like yours. I switched the lights off, and I could see the tube cap was glowing purple, like with a heavy static discharge. Looking closely at that cap, I saw it was cracked, and bleeding HV.
Of course, most of your HV stuff is UNDER the chassis, so you'll probably have to pull the whole mess out, and run the tv on its side on your workbench to get a visual on that hissing sound's source....
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#8
10-22-2010, 12:43 PM
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I believe Corona Dope is classified as a rather nasty substance so the shipping tends to be high.
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#9
10-22-2010, 03:20 PM
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I bought sensor safe rtv at the auto parts store. Worked great for my Zenith. Sensor safe is acid free.
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#10
10-22-2010, 03:29 PM
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Exactly! the stuff that smells like vinegar can eat copper wire/ circuit board runs.
http://newsgroups.derkeiler.com/Arch.../msg01830.html jr
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#11
10-22-2010, 03:51 PM
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Sensor safe RTV... sounds like a good idea. I don't think I need anything "eatting" my flyback. I was just at AutoZone awhile back with my dad. Maybe I'll check there and Advance and see what they have.
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#12
10-24-2010, 09:30 PM
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I was just thinking back on something that I thought I'd throw out there. It seems like when I installed my 4uF capacitor which filters the 12BY7 video amp, I seem to recall that I got the capacitor awfully hot. Seems like I had some trouble positioning it or something and the 100uF that filters the sound take-off coil is right next to that and shares a ground terminal. These capacitors were awfully little compared to many I put in. I wonder if I just got them too hot and damaged them.
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#13
10-26-2010, 06:56 PM
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RTV'ed the Flyback
I went out today and got some sensor safe blue RTV to coat my flyback. I coated the bottom half of my flyback where the wax came off, which effectively covered it a blue "icing."
 After powering up the set and monitoring it, I've noticed now that that the "hiss" is gone, along with that troublesome blue arch. Still another trouble remains...  I kept hearing a little "tic.. tic, tic..." coming from somewhere down here, and this time it doesn't seem to be arching from the flyback itself. I turned out the lights and could make out a faint little arch jumping from somewhere on this copper-colored thing to the cadmium-plating support bracket below it. I didn't hook up an input, but noticed that I couldn't seem to get any horizontal sync. I'm inclined to think that there's a bare spot in one of these wires going to or from the 1B3 that's leaking somewhere.
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#14
10-26-2010, 10:45 PM
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I see a fair amount of dust and such on that tan colored piece of plastic. That dust and dirt can create leakage paths for very high voltage. Cleaning it may get rid of that tic-tic-tic.
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