You are in deep poo. I have seen exactly this failure in a player I have here for repair. It is reparable but requires surgery depeinding on the extent of the damage. You probably had a loose screw in the case that dropped into the back corner of the PCB when you previously picked it up to carry it.

It's unlikely the schematics will go public. I have not got permission to release them, I'm fraid.
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One of the few remaining Mk1 owners... #00015