I would recommend checking a few places.
#1. Inspect your ball count unit. Verify that it is moving properly. Examine the coils and wire connection. Clean and adjust the rivets on the bakelite.
#2. Inspect your outhole switch. Clean and adjust as necessary.
#3. Inspect your player unit. Verify that it is moving properly. Examine the coils and wire connection. Clean and adjust the rivets on the bakelite.
If you have questions about doing any of these steps, visit http://www.pinrepair.com/em/index2.htm#steps for more details.
Marcus