As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMB-OUT AT 500 FEET ALL 4 EGT AND N2 INDICATIONS WENT DARK THEN CYCLED ON/OFF IN FLIGHT. POWER LEVERS WERE NOT MOVED DURING INDICATION LOSS. ONCE DECISION WAS MADE TO RETURN, DURING TURN, INDICATION CYCLED ON/OFF. REPLACED RELAY EM2. PERFORMED OPS CHECK OF ENGINE DISPLAY PANEL W/ALL 4 ENGINES AT TO POWER.