ADTECH QS7AA020M is the X axis servo driver for the custom built CNC Lathe machine.
Few months back this driver just stop working. And then I did quick reverse engineering thing. Problem was its SMPS ic TOP244YN is in thermal shutdown mode. It was a internal issue. So I replaced the part and put it to the service.
And then after 3 months of continuous service it did the same thing. And now this time SMPS ic TOP244YN and the voltage reference ic TL431 both fail.
However again its working fine after the repair.
But im bit confuse why on earth its internal smps give up time to time.