What was found
AIRCRAFT OWNER STATED THAT UNIT QUIT WORKING IN FLIGHT. REMOVED GPSCOMM FROM TRAY AND FOUND THAT PINS 21 & 25 HAD ARCED. FOUND THAT GPSCOMM WAS NOT SEATED PROPERLY IN TRAY AT TIME OF ORIGINAL INSTALLATION BY GULF COAST AVIONICS. REPLACED CONNECTOR & DAMAGED PINS 21 & 25. THIS COULD HAVE BEEN PREVENTED IF THE ORIGINAL INSTALLER (GULF COAST AVIONICS) HAD VERIFIED THAT THE UNIT WAS SEATED PROPERLY & CORRECTLY IN THE TRAY.