Normally when you get a fault like this its the defrost heater that causes it.
What you can do is empty the freezer and remove the back panel inside there.
From there you will see the evaporator. Wrapped around this is the defrost heater. You will see the wires for it at the top of the evaporator.
Disconnect the wires and turn the appliance back on and if it starts up ok without tripping out then the defrost heater is the fault.
So replace the heater and that will cure the fault from there.
Check it out if you can and see what you find. If you need anymore info just get back to me.