Lec TF5517w – Going dead

I went to this fridge repair and found it completely silent and the fridge light on… so as it has a defrost timer fitted next to the compressor, I naturally just clicked it on manually and the machine came to life. Left it on test and oredered a new part.

As I expected it worked fine while on test until it came to a stop when it reached the next cycle period – Then fitted new part and all is good, text book repair I thought.

Then a day and a half later, customer calls me to say that the same problem has occurred?? Returned, advanced timer and its working again….. Am I missing something here or is the new timer just faulty?

Any help please?