HELP please - Antenna Genius problem resolution - Relay Operation

Stan VA7NF

An AG I'm trying to fix works well BUT: - Radio A and B both will select an available Ant 1-8 and connect that antenna to the appropriate radio with ONE EXCEPTION - Radio A will select Ant 3 properly but NOT connect the attached antenna to the radio. Radio B does work correctly to the same antenna.

Opening the box and getting down to the relay board (A difficult process at best) results in a single board with three banks of 8 relays each. The relay on the failing side (A) shows major black burn marks on the plastic that was likely caused by 1KW into a high SWR feedline between tuner and antenna.

Replacement relays were ordered (with the same part manufacturer and part number) and replaced (Also a difficult process desoldering 8 pins concurrently) BUT the same problem remains. Radio A will not connect to Ant 3 where Radio B will.

Is there a circuit diagram available or anyone who has serviced this box that can give guidance?

Note: Really avoid having high SWR on the coax between tuner and antenna going through this AG box. It is not hot switched!