There is a short on the hammer drive circuit. It can be caused by the
HammerBank
TALLYGEN 093524 HAMMERBANK T6306 Refurbished
The Main Logic, the link is for the standard one, but if you have a Graphics selection then you will need a different one.
TALLYGEN 086153 CONTROLLER KIT STANDARD T6306 Refurbished
And in rare cases the hammer bank cables, but you will normally see a break in the cable if that is the case.