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#1
05-10-2011, 12:46 AM
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After you check the deflection coil, check R3, the vertical linearity control and R4 the vertical size control.
I assume you've already checked V13 the 6C4 and V14 the 6V6. The way they've drawn the alternate circuits is confusing to me and I'm not sure where this section is getting it's B+. I might have to pull my chassis and see what they really did. John 
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#2
05-10-2011, 03:52 PM
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"The easiest place to start is with the vertical deflection coils (the ones on the neck of the CRT) - check them for continuity with a multimeter."
Forgive my new guy ignorance but I don't know how to do that. I know how to check continuity with a meter but I'm not sure where you're suggesting I check. Could you elaborate on that some more for me? "After you check the deflection coil, check R3, the vertical linearity control and R4 the vertical size control. I assume you've already checked V13 the 6C4 and V14 the 6V6." I've tested V13 and V14, they both check good. I've also adjusted R3 and R4 to no avail. "I might have to pull my chassis and see what they really did." Wow! You guys are so helpful here it's hard to believe. Please don't go that overboard for me yet. Let me do some due diligence of my own before we get to that point.
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#3
05-10-2011, 06:09 PM
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Quote:
 But, we're always happy to explain if you don't understand. I suspect the terminology we throw around doesn't help either...If you look at the back end of the picture tube itself, you have the end that is wired up to the rest of the set, where the guns are. Moving forward towards the wider [bell] area of the CRT, you may encounter some rings with a bunch of tabs on them [purity magnets]. You won't need to touch those at this point. Further towards the bell, around the part where the tube begins to widen, will be a cone-shaped form [the deflection assembly, AKA the yoke]. This contains the coils of wire that the set uses to move the beam of electrons within the tube. One pair of coils is for the horizontal deflection of the beam, the other pair is for the vertical deflection. (from the picture in the first post, yours appears to be boxed in in that metal cage that rises up from the main chassis). Essentially what you want to do is find where those are wired to the rest of the set, and use those points to test each of the vertical coils in the deflection assembly for continuity. If it's closed in, you can't tell which leads go to which coils, so you'll have to go by the schematic. I don't have one on hand, so perhaps another member can tell you exactly where they are. You should be able to locate them by wires running to the vicinity of the vertical components just mentioned (R3, R4, V13, V14). If you get an open reading on one of them, then there's a break in that coil, and you've found your problem. If not, then the problem is somewhere else... and hopefully it is, because coils aren't exactly easy or fun to repair. Apologies for the wall of text, but it'll have been worth it if you learned something, and my job will be complete for today Quote:
Last edited by VintagePC; 05-10-2011 at 06:18 PM.
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#4
05-10-2011, 08:56 PM
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From what I can tell there is continuity across the coils. I looked at the schematic and I think the areas I pointed to in yellow is where to test.
 I pointed to those leads in yellow below and there is continuity across those two leads. For some reason the wire on the output side of the transformer is soldered on a "landing strip"(I'm not sure if that is what you really call it but that is what I came up with). Maybe it's so you can test things easily, it certainly did make it easier for me.  Could the next step be firing the set up and testing voltage out of the vertical output transformer(T4)?
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#5
05-11-2011, 12:21 AM
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Quote:
Anyway, be careful with the vertical output tube plate, when it's working normally it has pulses about 1 to 2KV tall. Before firing up the set, check that you have continuity on the primary of the vertical output transformer. Likely a few hundred ohms. Oh, on the yoke, getting continuity across the secondary either tells you the yoke has no opens or the secondary has no opens. Or both have no opens. You'll have to disconnect a lead on one of these to tell for sure.
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#6
05-11-2011, 10:54 AM
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Besides T4, you should also check for continuity on both the primary and secondary of T2 in the vertical oscillator. That one will be easy because you won't need to disconnect anything.
R3 is in the cathode of the vertical output and sees quite a bit of power which is hard on it. You should check to see that it has the correct resistance. R4 supplies the plate of the oscillator and could be bad too, but it doesn't see as much power. You might need to try substituting the 6C4 also even though it tests good. It might have too much grid leakage which might not show up on your tester. John
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#7
05-11-2011, 12:10 PM
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T4's secondary reads spot on at 7.5 ohm. T4's primary which is supposed to read 700 ohm is reading twice that 1.4 k ohm.
T2's secondary which is supposed to read 1.3 k ohm is reading 1.4 k ohm. I'm assuming that is well within accepted tolerance levels. T2's primary is supposed to read 160 ohm. It is reading wide open. R3 is good to go at 5 k ohm and adjusts as I turn the control. The tester that was used to test the 6C4 had a leakage detector and it tested good there to. So it looks like my problem is T4 and T2? Are those parts that one can find?
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