Tech: Don't replace that Rock Ola Logic board just yet

This pertains to the Rock-Ola 478 but may apply to other models.

If your logic board does not pass the 'TEST' by using the test switch
on the board then your problem may be IC402. If the 'Timer LED' does
not flash when the carriage rotates then the most probable fault is
the dual timer at IC402. I have used a replacement part from Radio
Shack with perfect results. Radio Shack part# is 276-1728 but any
electronic supplier can cross the number '556cn'.

Hope this helps someone.

Tim