Dimmer does not work on lower positions

[adnansarwar2050]

I am trying to repair my fan dimmer. It was working on maimum position only and was not working on lower points i.e was turning the fan off instead of being slowed down. I have replaced both diac and triac but still the same condition. Which component in dimmer has the most probability to be damanged

 

[D.A.(Tony)Stewart]

any of the other parts or wiring error
https://www.circuitstune.com/2012/01/ceiling-fan-regulator-speed-controller.html

 

[adnansarwar2050]

Its on PCB. Resistors are ok. capacitor also seems to be working, i have replaced Diac and Triac both but still not working

 

[FvM]

Broken potentiometer?

 

[D.A.(Tony)Stewart]

Does this one have of those chain pull rotary switches with fixed R's? Check switch?