We have a 10 year old Frigidaire Refrigerator Model FRT21H7ASB3.
About 4 days ago, the refrigerator temp got warmer while the freezer remains perfectly cold. In the past, the door had not closed completely so we just assumed the door had been left open and that warmed the frig. We've been monitoring the door seal and that isn't what is occurring now - at least the door has been closed while the temp remains warm.
I pulled the fridge out and did notice dirt/lint collecting on the vents but they were not obstructing the air flow. There is a panel that can be removed but, I'm not certified and I would hate to damage the appliance.
I looked into the problem that seems to be occurring and I found the following helpful site:http://www.repairclinic.com/RepairHelp/How-To-Fix-A-Refrigerator/58---/Refrigerator-freezer-is-cold-but-refrigerator-is-warm
Looks like several options. Key is whether a repair call to assess the actual problem and install a part is worth it if a replacement frig might be the better option (maybe the same or just a little more cost and we would be replacing a 10-year old appliance. If it's the Damper that seems like an obvious replace and fix option. If it's one of the more expensive fixes, the replace option seems better.
The other considerations are if a part is available (out of stock on the site linked above) and the time it takes to get it - all while the frig is not functioning correctly.