Quoted from FatPanda:Just acquired a ToM and noticed that sometimes it doesnt detect a ball drain. Upon further investigation, it appears that when the ball rolls into the trough, it isnt rolling down all the way and gets stuck in the track of the trough somehow. Any simple fixes i could do? I took the trough out and cleaned it with simple green but balls sometimes still get stuck.
This will probably solve your problem:
http://www.pinbits.com/index.php?main_page=product_info&products_id=449