3 head mini split system. Main living room head indicates a C5 error code which means that is miss communication between the indoor and outdoor unit. The other 2 heads are operating properly, tech switched the wires to the outdoor unit and indoor unit to eliminate the outdoor unit being a challenge and the error code still persisted. Tech inspected the indoor control board and found corrosion on the board elements. Tech was not able to find service facts for blue ridge mini splits. Tech recommended to replace the indoor control board along with the main display transmitter. Tech informed the customer over the phone and requested quotes on replacement of the indoor control board and display transmitter and also a quote on how much would cost to replace a customer supplied mini split head if he were to get one and have us recover the system, install the mini split head and charge the system back up. Data tag for the outdoor unit was not readable and tech does not know how much refrigera