OK, thanks for that.
This normally happens when the compressor is faulty and/or has jammed.
It heats up extremely quickly and trips the overheat protection.
As it cools down, it tries to start again and trips the protection again.
Unfortunately this normally requires a new compressor and a regas.
You would be looking at an expensive repair I'm afraid.
You need a refrigeration engineer to change the compressor and regas the system.
I'd guess at least £150 but more likely around the £200 mark.
Sorry, not good news or an easy fix.
I wish it was as simple as pressing a few buttons.
Hope this is of some help
Let me know how it goes or if you need more help