Electrolux Er2650B Fridge Freezer Blowing Room Temp Air

[joko]

My frost free fridge freezer has stopped blowing cold air.

it seemed like it was still blowing cold air, but i think it was just because some things in the back of it were still frozen.

ive checked all the seals - fixed one & added vaseline so its pretty tight now, but its not changed temp

the lights, fan, motor etc are all on & seem to be working fine.

ive turned the thermostat wheel until it clicked off, then clicked it on again, but nothing changed

Has anyone got any ideas of things i can check or do or adjust etc to fix it - BEFORE i get to needing new parts etc?

I dont want to start buying new bits or a new FF then discover i could have just adjusted something or whatever

thanks :)