[Jaci]

We were having this same issue at the Australia Regional. After a while, we narrowed it down to the following 2 things:

a) The Circuit Breaker (and the wire that connects it to the PDP)

b) The Anderson Battery Connectors going from the Breaker/PDP to the Battery's Anderson Connector.

Replacing these seemed to solve our problem for all our future matches. Some breakers can be very sensitive to sudden stops (i.e. crashing into a defense), and faulty Anderson connectors was discussed in another thread.

EDIT: We diagnosed this by looking at the DS. If the comms go down, then comms go up and (later) code goes up (checking DS logs to confirm the signal loss was indeed with the radio), it means the total system did a reboot (radio AND rio), so you can usually diagnose that as the main power feed to the PDP (or the PDP itself), as the RIO and VRM (connecting the radio to power) are on separate connectors.