Fridge not cold in fridge/freezer (Whirlpool ARZ 5290/H)

Hi folks,

Fridge/freezer (Whirlpool ARZ 5290/H)

Recently some forgetful people have left the fridge door open on a regular basis and as of 2 days ago the fridge does not get very cold (down to 10 deg C?).
Its a dual compressor system with a frost-free fridge and the freezer works fine although it does need regular defrosting, due to poor seals.
It might be the compressor, relay, thermostat, defrost heater,defrost thermostat, no or low cooiling gas....?
I have read that a common fault on leaving the door open is for the evaporator to freeze over although the back wall does not feel cold, the base felt cooler, so why should I suspect ice there?
There is a fan that works fine but that just seems to circulate air around the fridge interior so I suspect the cooling is going on via heat transfer through the interior fridge walls.

Don't really want to have to switch off everything and de-frost for 48 hours as the freezer is full and has no home to go to.
Any ideas?
Cheers,

Daniel

frost free really means frost hidden, and I assure you they hide it well, so they do indeed freeze up very good, especialy if the fan gets weak or is stopped by the ice, they should be going into defrost mode every x houres of the day, so could be fan or timer issue at hand?

just a couple things to consider, very rarely ever will it be the gas!

Fan or timer? Don't even know where they are. The fridge is a sealed unit on the inside. Would it be in the back cavity or in the base on top of the freezer part?

small domestics aren't really my specialty, best I can say is let it defrost, get a good cooler to put the food into and if it runs good after that then chances are just so much has built up it stalled the air flow so the mixing port wasn't geting enough air pushed through.

I'll step out and allow some one with more indepth experiance to step in, but like I said, my first step is a manual defrost then move forward from there!