PANASONIC NN-SD25HB MICROWAVE FOR REPAIR OR PARTS ONLY

PANASONIC MICROWAVEW OVEN NN-SD25HB MODEL NUMBER FOR SPARES OR REPAIRS BRIEFLY SWITCHED ON THEN OFF SOMETIMES GIVES ERROR CODE I THINK H90. OTHERWISE IMMACULATE CONDITION. SOMEONE KNOW HOW TO FIX WOULD BE A GREAT BARGAIN OR ITS PARTS CAN BE USED.