Hello All,
As usual I have replaced all paper and filter capacitors. I have tested the vertical oscillator/output tube 6CG7 and it tests very good. I have found and replaced every last paper and filter capacitor even the ones that were hiding behind things. All of them. This chassis is very tiny but everything fits.
Could it be an off value resistor? I don't even see a disc capacitor in this circuit.
The fold-over is on the top of the picture. The lower part is fine.

Thanks,

Dave...

This is the red model so it could be 7011, or 7012.

All in all, if you are having trouble with the virtical circuits, you should be examining all components in the vertical section. No component should be overlooked. I am mentioning likely components below, but every component should be checked, just the same, and every component should have one wire unsoldered to insure accurate results.

Check for trouble with the resistors in the cathode circuit of the vertical output tube. Check for a heater to cathode leakage in the vertical output tube. Of course, check all resistors in the vertical circuit to be sure. You must unsolder each one (one lead) to test them accurately. Don't test them while they're in the circuit.

The values of the condensers used in the vertical oscillator and discharge circuit are critical, and should not be changed to different values. These would be condensers connecting to the grid and plate of the tube. One on the plate should bypass the signal to the output tube, and the other should bypass certain frequencies to ground through various resistors, perhaps including the cathode bias resistor of the output tube.

If any resistors are used across the vertical deflection coil (inside the yoke), make sure none of these have opened. This would more likely cause faint dark ripples at the top of the raster, but you should check them just the same.

Be sure that, if circuits are shown connected to certain bias voltages other than B- (such as being shown to -100 volts or something like that), that those designated biasing voltages are at their proper values. If they are not within reason, you could be having power supply issues as well, although this would likely cause trouble in other circuits like the horizontal circuits, which you say function normally.

Thomas

:All in all, if you are having trouble with the virtical circuits, you should be examining all components in the vertical section. No component should be overlooked. I am mentioning likely components below, but every component should be checked, just the same, and every component should have one wire unsoldered to insure accurate results.
:
:Check for trouble with the resistors in the cathode circuit of the vertical output tube. Check for a heater to cathode leakage in the vertical output tube. Of course, check all resistors in the vertical circuit to be sure. You must unsolder each one (one lead) to test them accurately. Don't test them while they're in the circuit.
:
:The values of the condensers used in the vertical oscillator and discharge circuit are critical, and should not be changed to different values. These would be condensers connecting to the grid and plate of the tube. One on the plate should bypass the signal to the output tube, and the other should bypass certain frequencies to ground through various resistors, perhaps including the cathode bias resistor of the output tube.
:
:If any resistors are used across the vertical deflection coil (inside the yoke), make sure none of these have opened. This would more likely cause faint dark ripples at the top of the raster, but you should check them just the same.
:
:Be sure that, if circuits are shown connected to certain bias voltages other than B- (such as being shown to -100 volts or something like that), that those designated biasing voltages are at their proper values. If they are not within reason, you could be having power supply issues as well, although this would likely cause trouble in other circuits like the horizontal circuits, which you say function normally.
:
:Thomas

All recomendations previously mentioned should be helpful. Also the vertical output transformer is a likely cause for vertical foldover. I have disassembled problem transformer cores and reassembled with care after inserting a THIN insulator between the ends of the Es and the Is (soft iron core laminations) to eliminate core saturation. Also, reverse the orientation of the Is relative to the rest of the transformer could make a difference. If assembly/disassembly of the core makes a noticeable difference, this could indicate trnsformer core saturation, and the resultant nonlinearity in output. Look at voltage waveforms on the output tube grid, cathode, and plate.

Also, the 6CG7 is not the output tube. The last number in the output tube is likely a 5. Good luck. Also, SUBSTITING the output tube, not just checking it, is a necessity because the vertical circuit condnditons are much different from the tube checker!

As always, Thomas has provided very comprehensive troubleshooting information.

In addition, the following technique provides a quick check of resistors in circuit (with the set turned off of course):
An in-circuit resistor measuring higher than it's rated value is most likely defective. Usually the measured value is lower than the resistor's rated value because of parallel resistance paths. In this case, one lead must be unsoldered to allow accurate measurement.

:All in all, if you are having trouble with the virtical circuits, you should be examining all components in the vertical section. No component should be overlooked. I am mentioning likely components below, but every component should be checked, just the same, and every component should have one wire unsoldered to insure accurate results.
:
:Check for trouble with the resistors in the cathode circuit of the vertical output tube. Check for a heater to cathode leakage in the vertical output tube. Of course, check all resistors in the vertical circuit to be sure. You must unsolder each one (one lead) to test them accurately. Don't test them while they're in the circuit.
:
:The values of the condensers used in the vertical oscillator and discharge circuit are critical, and should not be changed to different values. These would be condensers connecting to the grid and plate of the tube. One on the plate should bypass the signal to the output tube, and the other should bypass certain frequencies to ground through various resistors, perhaps including the cathode bias resistor of the output tube.
:
:If any resistors are used across the vertical deflection coil (inside the yoke), make sure none of these have opened. This would more likely cause faint dark ripples at the top of the raster, but you should check them just the same.
:
:Be sure that, if circuits are shown connected to certain bias voltages other than B- (such as being shown to -100 volts or something like that), that those designated biasing voltages are at their proper values. If they are not within reason, you could be having power supply issues as well, although this would likely cause trouble in other circuits like the horizontal circuits, which you say function normally.
:
:Thomas