Sounds like the machine is a tiny bit out of time. This would be a good time to take the head in and have it checked for timing, setting both tensions, and checking for worn or broken parts. They should have a test stand to drop the head into. Let me know if Ariel can do that, it would save me an extra 2 1/2 hour drive. Most places are lost if you bring them an industrial machine.
No one lives forever, the trick is creating something that will.