Whirlpool sxs refridge only gets down to 55 degr. Cleared ice out of the top compartment where the cold air comes out. Not cold enoug still

What should I check? Did I need to defrost longer? ( Used hair dryer to melt ice in compartment). Freezer is very cold, I opened the sliding doors to the fridge side to get more freezer air. Seemed to help at first, but now back to 55 again. Hear it running because it stops at off pos. tried turning freezer up, down, no change. Can't call repair guy because that's what my husband wanted to do, and I want to be right. Hate to pay for a defrost, what else can I try? ( besides he is almost always wrong)