I tried searching online and found many issues stating that the fridge is working but freezer isn't (or both aren't working) - with my unit the fridge is fine but freezer stopped worked ~12-18 hours ago.

To start, I have a Sharp SJ-X5406 that I purchased ~4 years ago and has been great up until now. I took the freezer compartments apart and noticed a buildup of ice in an area that had a metal rod and many pieces of thick aluminum sticking at. I melted the ice by spraying small amounts of hot water (was afraid to chip away at the risk of damaging something), and got it free from ice. Keep in mind at this point it's been 12-18 hours by my guess that the freezer stopped working and ice cubes are starting to melt, while this isn't showing signs of melting.

Just above and behind this rod I can see through the a vent a fan. Now every time I open the door the fan runs for around 3-5 seconds and then stops. If I close and re-open it happens again. For the life of me I can't recall if this runs all the time, but I imagine this is part of the problem.

I'll be calling a technician tomorrow as I'm not sure what the issue is, and I wouldn't know what I'm looking at also. If anyone else has any ideas of something I could try I would appreciate it.