OK, good. That is pointing to the optical interrupter. It may have been useful to report the actual minimum and maximum voltages coming out of the interrupter since this is essentially a analog to digital converter. It would be interesting to know which half of the interrupter failed. P102 pins 2 and 7 would tell us if the LEDs are drawing current.
Good work on finding the replacement. My next question would have been are there any numbers on the interrupter. Don't forget to check the bias and mechanical adjustment after you put the new one in.
73
-Jim
NU0C
On Sat, 24 Feb 2024 20:40:15 -0800
"K6OXN Bob" <bobk6oxn@...> wrote:
I did follow the schematic, and I apologize for not reporting the voltage readings. TP101 reads 1.112 vdc and TP102 reads 8.31 vdc. TP101 does not vary when turning the tune dial, but TP102 varies when I turn the dial.? U101 pin 1 reads 1.112 vdc and pin 5 reads 5.41 vdc and pin 1 does not change with movement of the tune dial, while pin 5 does vary. This led me to believe the Optical Interrupter was at fault since I can change the direction up or down with changing U1 and U2 of the optical device.? Again I apologize and will try and keep everyone informed in the future.
--
73
-Jim
NU0C
Jim Shorney