I have a hotpoint fridge freezer, model ffm90, with a very noisy fan. The fridge and freezer are both still cooling, and seem to be working normally. The fridge fan noise has been getting worse for a while, and it is now very loud. Pretty sure it's the fridge rather than the freezer as opening the fridge door shuts it up. How do I access the fridge fan to check it or replace it? I've removed a vent cover inside the fridge, which just seems to lead to a pipe heading downwards, and no sign of being able to reach the fan that way. Thanks for any help!