Just acquired a Bally Star Trek in non working condition. Power supply is bad and I have ordered new bridge rectifiers. One TIP is bad and a fried resistor on the solenoid board which I will replace (along with the electrolytics). Now on the MPU, which the previous owner said was bad, there is a jumper between E11 and E25. When I get the unit powered up for the first time, should I leave this jumper, or should I remove it? I don't understand what it is for. Thanks for any help here.