Connection between display and power bar board lost

[ChrisC]

Thanks for the clarification, I was running each sketch independently of each other with the Robo Tank sketches running on the other boards. So running all three test sketches simultaneously I get the following from the serial port on the display:

Initializing sd card...
SUCCESS - sd card initialized.
Wait 5 seconds for test to begin
Serial1 Sent Signal to Power Bar

Does this indicate which board at fault? or is there some way to diagnose where the problem is.