Looks like error code 83-7 is for "Game History" error, you may need to clear the cmos ram if it is corrupt somehow. In case that is what is needed I've attached the clearing procedure below. But this may be off the mark since changing bulbs shouldn't have caused the cmos ram to get scrambled, unless you also replaced the battery?
Bally ProSlot 6000 Malfunction and Game Codes
803 ROM checksum error
813 Battery low
82 Door open with power off
833 SafeRAMTM error
83-6 Personality SafeRAMTM
83-7 Game History
83-8 Option Table
83-9 Bill Record
83-A EFT History
83F SafeRAMTM format error
83F-0 Invalid SafeRAMTM EPROM
83F-1 Invalid main EPROM
83F-3 Invalid coin denomination
843 RAM Error
85 MPU removed with power off
86 Secondary device communication fault during game after failure of the second attempt to reestablish communication.
87-x Memory Failure during Win Evaluation
88 Catastrophic failure
89 AFT cashout to Host failed