Komatsu Main Controller

I have a Komatsu PC 220 LC6 & paid the dealer to tell us our the part # R7834-21-7002 Controller needs replaced (wow that hurt). All functions work except the swing. We have the controller by-passed with the by-pass topple switch. The controller is $ 2500.00 +, can or does anyone repair these controllers ?

Thanks

Komatsu Main Controller