Panasonic American-style fridge freezer warm in top of fridge

[Seb9662]

My Panasonic NRB54X1WB American-style fridge freezer has suddenly got warm in the top half o the fridge (started a few days ago). The compressor is running; the freezer is working normally and the bottom half of the fridge is still cold.

This is a model with separate evaporators for fridge and freezer, and a 3-way valve to direct the coolant between them, so it can't be due to blocked ducting between the two compartments.

The self-diagnostics mode reports no faults.

I can't tell if the fridge fan is working or not. But looking at the service manual , if the fridge fan had failed, the self-diagnostics should report this?

Another option might be the 3-way valve. But would the bottom of the fridge be cold (6 degrees ish) if the 3-way valve was stuck on 'freezer'?

Anything else that could cause this?

 

[opps]

I would be checking the fan. I have no idea how efficient the diagnostics are.

 

[Seb9662]

Thanks opps. In the end I did a big defrost and also disassembled the interior. The fridge evaporator was totally encased in ice. Since the failure was sudden, I suppose the ice must have grown to the point where it either blocked rotation of the fan or blocked off a channel for air flow. Confirmed the fan runs by running the fridge with inside panels removed, cleaned out the condensation drain for good measure, reassembled, and it seems to be working properly now!

 

[foxhole]

Have you noticed any clicking when the door is opened, indicates ice around the fan as it turns off whenever the door is opened? and fan blade hits ice building up.