Kenmore refrigerator won't cool, but freezer does. We have a Kenmore fridge model # 106.56239400

Question

We have a Kenmore fridge model # 106.56239400 and the fridge side is set to the highest setting and is just barely cooling-not cool enough to store milk. The freezer side is fine. We had a tech out today from some fly-by-night company and he couldn't figure out the problem. After talking with his boss on his cell phone, the boss decided it was the computer board. If it is in fact the computer board, where is it located, can I pick one up, and is it difficult to replace? any help is greatly appreciated as they claim this fix will cost $400.00!! Refrigerator section is too cold, even on lowest setting. Have freezer setting on the coldest to keep the small door between refrig and freezer closed to keep cold air from freezer out. Would just unplugging for awhile reset everything and solve problem or would it be another solution? [e-mail]