This is a coin op washer purchased in 2008. It has been problem free up til now.

Whats happening now - When I pushed start button, light illuminated with a click but just a hum sound. When I release button light goes off with a click.
Note: I replaced the door lock mechanism and it worked for a few weeks then it started to have problems again. The door lock mechanism will click and light illuminates with the door open. Not sure if the new one is still working properly.

I replaced main timer and had a different result: Light just stayed on and start button had no effect (clicking sound) The timer was installed in wash cycle. I went back to original timer. I also replace start mechanism motor with a new one. No change. Not sure how to test components individually. I replace control board with a refurbished board and same results. I used to get it running buy pounding front panel area or tinkering with start mechanism and it would start ad go through whole washe cycle.

I also cleaned the drain pump of debris found a coupe pennies and some lint. Impeller looks fine. Any ideas? I can troubleshoot and try any suggestions