What was found
INTERMITTENT AND COMPLETE FAILURE OF EHSI, COMM NR 1 AND GPS SIMULTANEOUSLY WHILE IN CRUISE FLIGHT. HAPPENED TWICE FOR APPROX 1 TO 2 MINUTES. CHECKED ALL CONNECTIONS EHSI, COMM NR 1 COMM, GPS RESEATED ALL CONNECTIONS OPS CHECK SAT. ON GROUND. AFTER START THE GPS, COMM NR 1 AND EHSI DO NOT HAVE POWER. WILL COME ON AFTER RESETTING AVIONICS' MASTER 2-3X. REPLACED K136 RELAY SYSTEM OPS OKAY.