Trying to fix my first pinball machine, Bally Rolling Stones. Everything seems normal until press the credit button. The game starts (most of the time), but the sound (a tone from the speaker), pulses with the flash of the PF lights. Also, when I press more than one player, the TILT comes on affecting the first player only first ball. Another issue maybe unrelated to the pulsing sound or not...the three pop bumpers are weak and sometimes more than one will energize at the same time. The bumper switches appear to be gapped ok. I have swapped the solenoid driver board with a good one and didn't change anything. I have checked the power supply test points and have good voltages. I have run the solenoid and switch self tests and all solenoids fire and no switches are shown to be closed. I am having to replace the play field fuse every few troubleshooting attempts. All fuses are correct ratings. Any suggesting or solutions? Thanks for any help.