Another fridge water-pooling question

[fsa297]

My Zanussi ZRB32213WA is pooling water at the bottom of the fridge compartment. So far I have:

• Left the unit turned off to defrost.
  
• Stuck a 30cm zip tie down the drain hole and jiggled.
• Blew air down the drain hole through some tubing.
  
• Put bicarb soda and vinegar down the drain hole.
• Checked the drain tray at the back to find it completely dry.
• Used a Pela pump down the drain hole and tried to aspirate.

Any other tips to try?

I was considering removing the tubing from the back of the fridge to investigate, but the back panel is covered with, what seems to be, a corrugated plastic panel. Is this easy to remove?

 

[jj4091]

Is the fridge level front to back?

 

[JohnD]

• Stuck a 30cm zip tie down the drain hole and jiggled.
• Blew air down the drain hole through some tubing.
  
• Put bicarb soda and vinegar down the drain hole.
• Checked the drain tray at the back to find it completely dry.

this suggests that drain water is not going down the pipe. Is the gutter correctly fitted to the pipe? Is there a pea in the gutter spigot?

Can you blow up the pipe from the evaporation dish end?

 

[fsa297]

I used a spirit level to check and it is level.
How do I check if the gutter is correctly fitted to the pipe?
I can't seem to put a pipe or anything in from the evaporating dish end as there seems to be bend or something a few cm above.
From the top end, the pipe seems to be clear as I managed to put a drain unclogger tool thing down it for about half a metre.