Just because the knob does not advance does not prove that the timer is faulty. You have to distinguish between the movement of the outer knob, the advance mechanism, and the conditions that allow the cycle to continue.
Check that it is a mechanical control
This diagnosis applies to electromechanical or spring-wound timers. A digital counter that resets the duration belongs to the analysis of remaining time and paused program.
Identify the control on the model: two similar knobs can drive different mechanisms. Do not force the shaft or turn it beyond the allowed directions to check whether it releases a stage.
Separate three behaviors
- The outer knob turns without driving the shaft: check its connection and possible breakage.
- The mechanism does not advance: check its operating conditions and those expected by the cycle.
- It advances but an operation does not run: investigate contacts, wiring, and the element that receives the command.
In a twin tub, the lack of washing or spinning may be outside the timer. An incomplete command or an irregular change in direction requires comparing the wiring diagram.
Identification and replacement
The replacement part is selected by reference and application, with the corresponding diagram. Electrical work must be carried out by qualified personnel, with safe isolation and a subsequent functional check.
Do not adapt terminals by color, lubricate contacts, or jump positions. The external arrangement of the connections does not establish equivalence between two timers.
Record whether the knob moves and which operation stops running; that distinction prevents confusing an external breakage with a switching fault.