Temperature Control. We have a Whirlpool Electronic A Class upright freezer mod AGF 7000/IX, made

Question

We have a Whirlpool Electronic A Class upright freezer mod AGF 7000/IX, made in Italy.

We cannot control the desired temperature. Stayed on -22 C.
Now the temperature is going down, it is on -4C and the red triangle is blinking constantly.
Someone quoted a fortune to replace the Electronic board, I dont even know where it sits.
Can you help? Thanks
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