46v is fine. Check at an actual solenoid lug for 43v too to rule out a connector issue on the rectifier board
Bad connectors from mpu j4 to driver j4 would be the next guess if it is not the PF fuse or rectifier connector. You can put the game in solenoid test, go the the solenoid decoder chip on the driver board and check the outputs for activity during solenoid test. Solenoid test in big game goes through every solenoid output used which is all of them except for the all high input pattern for #15, so all should pulse during its turn in sol test except the highest output.
*edit* nm its an alltek driver board. I dunno what they do to decode solenoids on that but still mpu j4 to driver j4 is important.