PinSound will almost certainly bring back sound and fix it up imo, which is annoying in some ways as it won’t solve the mystery.
To be fair to @AndyB53 I don’t know how many sellers/restorers would step in and fix a pin after the new owner had been pulling chips, sticking in random replacement ones etc, but as has been said already you should not have had to even open the backbox in the first place, unless you knowingly bought a project pin which this clearly wasn’t sold as.
I’d get the board sent off to @myPinballs, get it repaired and then you can recoup some of the PinSound outlay.
To be fair to @AndyB53 I don’t know how many sellers/restorers would step in and fix a pin after the new owner had been pulling chips, sticking in random replacement ones etc, but as has been said already you should not have had to even open the backbox in the first place, unless you knowingly bought a project pin which this clearly wasn’t sold as.
I’d get the board sent off to @myPinballs, get it repaired and then you can recoup some of the PinSound outlay.