The power supply in my Police Force is putting out a weak 5v supply. Before it was putting out 4.95v and causing the game not to boot. The key thing is I removed all connectors from the board except the AC input connector and it was still showing only 4.95v at the test point. The caps were original so I replaced all of those. This brought the 5v up to 4.96v and the game boots reliably now. I also verified there are no bad solder joints and damage to the board. However, I'm trying to bring it up to at least 5.00v (for headroom). The 2N6057 power transistor was so old the markings had vaporized. After replacing this I saw no change.
I then looked at the MC1723CP regulator IC and pins 4 and 5 are showing 4.96v. This shows the circuit is balanced. I also verified the 9.8vAC coming to the board. What else could I check? Should I still replace the original 30 year old regulator IC? Or maybe replace the bridge rectifier in the event the voltage from it is slightly low?
I also considered the possibility there is a resistor that is off somewhere else is the circuit causing the MC1723CP to become miscalibrated against the 5.00v output it should be. I just want to bulletproof this board now before it goes out on location where it will run 24/7 365 at a laundromat.