GE GSS25UFMAWW serial# DA17323

Noticed a few days ago ice forming on the inside the freezor compartment on the rear panel over the evaporator. I thawed it out fully and restarted. the temp in it is now starting to get warmer and I think it is just not going into defrost. Is there anyway to manual check for defrost like on heat pumps?

Is this a common problem on GE side by side? Anywayto troubleshoot the defrost sequence?