Hi Everyone! I’m Sam, the senior electrical engineer  from Cosme Laser. To facilitate our clients to get after-sale service in time when meeting problems during the period of using our products,  we decide to share solutions of some typical cases that we once faced in our blog since 2019. Our interpreter will translate my understanding and advices of these problems into English accurately. There is no doubt that it will substantially save the time on both sides.  Your further question is much welcome.