How can i fix Hotpint Freezer Mistral FZ60P (No.18100842)?

I have a Hotpoint Mistral freezer model FZ60P No. 18100842 (R134 a), which has intermittent operating fault. The compressor motor (Danfass 102G) stays very hot and operates for few seconds and than switches off for a while and than switches on again for few seconds. This keeps on repeating and freezer does not stay cold at all. With the Fast Freeze switch on “0” and Economy switch on “0” or “I”, the Red and Green lights stays on. With the Fast Freeze on “I” and Economy on “0” or “I”, the Red, Green and Amber lights stays on. During this setting the motor keeps on switching on and off. Disconnected the freezer for 24 hrs and started again, but have the same problem. Is there a sensor or thermocouple problem, which is not passing the correct message to the compressor motor?