I have a GE fridge model# GBS20KBPACC, freezer on the bottom. A few months ago there was a problem with it defrosting and a repairman said I probably needed a new motherboard. After replacing that, the fridge was left plgged in, running, with no food in it for a few months. After putting food in it I discoved the fresh food compartment was only 50-60 degrees. The evaporator fan was running but the damper door would not stay open. I did block it open for a while and the temp did drop. I then spliced in a new fridge sensor and the damper will open for a short while but will not stay open. What do I do now?