I want you to remove the light lens in the fresh food side and advance the defrost timer till You hear a click and the compressor will shut off. You refrigerator is now in defrost go to the freezer and hold light switch in the off position and watch for a minute to see if You can see the heaters glow just like a toaster, You can see the glow through the louvers at the bottom of the back panel. here is what the timer and panel look like the advance knob for the timer can be accessed through the hole in the box behind light lens I circled the hole and timer in red for You>
It probably wont and You will need to replace this part>
Let Me know if You need anything else
Glad to hear I could help.