when you defrosted the coil, at the bottom of the coil is the heater. it is held in by 2 phillips head screws, one on each side of it. that is most likely the problem. ge has finally changed that single heater out to a double heater. i do replace a ton of them. the part # is wr51x10101. if you had an ohm meter to check it, you could verify it. it could be the defrost thermostat, or the defrost timer, but from what i see on a daily basis, i would go with the heater as an educated guess. if you need more help let me know. tom [url=]applianceeducator.com - parts[/url]