63 silvertone

[DaveWM]

The circuit rca2000 is a hold down circuit designed to limit HV output incase the shunt tube were to not regulate. It takes a negative voltage from the horz blanker grid and thru a voltage divider applies it to the grid of the horz output tube. was not used until the CTC-15, don't know about clones. the defect that would take place is a break in the trace on the edge of the chroma board, that would upset the voltage divider, providing too much neg voltage back the grid of the horz out, thereby limiting the power thru the tube and holding back the voltage.

You find this by checking the grid voltage of the horz out, should be about -50v if its a lot larger neg like -65v there is a good chance the problem with the broken trace exist IF THE SET USES THIS METHOD.

This would also show up in testing the horz out cathode current (it would be low).

This failure can also effect the brightness control as the too large a neg voltage also feeds the neg (dark) side of the brightness pot.
you can also check pin 2 of the horz blanking amp. this is the pin that has a 390k resistor to ground if its higher that 390k then the

A simple continuity check can be done by check from ground to the resistor that goes to blanker grid. Just look for the trace on side of the chroma board that runs next to the horz out. its pretty thin and is on the narrow side of the board.

I hesitate to mention all this as I would prefer to simply diagnose problems rather than jumping on every known problem in hopes of guessing right.

But if you have the chassis you may as well verify the continuity.

you can also check pin 2 of the horz blanking amp. this is pin to ground should not be more than 390k if so its likely the trace has cracked. the sams shows 220k on the resistance chart, but thats due to some other resistance in P with the 390k resistor that goes from the grid to the ground.