Hi, flickering, blanking screens showing crosses( display computerfault), errors with QNH/STD , rudder trim limit fault. FAC fault, are all problems which I see almost every day on the bus(along with window heat controller)
These sound very similar to the problems the BMI crew had except ours are caused by poor ground power units when sitting on stand with fluctuating voltages or handlers knocking the connector, and not at 36000 feet.
Possibly voltage spikes from faulty GCU?