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The white band across the screen usually means that you have insufficient vertical deflection.
You are using a schematic, right? The problem is in the circuits labeled vertical.
It sounds like you recapped the TV, so the first thing I'd do is re-check your work in the vertical circuits. You may have miswired a cap or installed one of the wrong value or pushed aside some other component so that it makes a short circuit or left behind a solder blob that makes a short circuit.
If the schematic has voltage and resistance charts, you can check the voltages and resistances on the vertical tubes. If anything is way off, you may have found the trouble spot.
If the schematic includes oscilloscope waveforms, you can hook up an oscilloscope and compare the waveforms that your TV is generating at the designed test points. If the ideal waveform is a sawtooth and your TV is making a flat line or some mutant shape, not a good sign.
You can check the values of the resistors in those circuits. The best way is to unsolder one leg of the resistor so there is nothing else connected in parallel with it.
If you don't disconnect the resistor for testing, then measuring a value significantly more than 20% above the listed value is often grounds for replacing it. However, if it tests below the listed value, then you are just measuring its resistance reduced by whatever other things are wired in parallel with it, so the test doesn't tell you much.
If the vertical circuits have any mica caps, those are worth checking. Micas are usually more reliable than paper caps, but they can go bad.
This is just general advice. Someone with the schematic could be more specific, perhaps.
Don't run the TV for long periods when it's showing a bright band across the screen. It may burn a band in the picture tube.
I have a Leader pattern generator that gives output on either channel 5 or 6. There's a switch on the front labeled RF Channel, 5, 6.
Phil Nelson
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