Hello Houlin Chen,
Thank you for writing in. We are sorry for any inconvenience caused on you.
Could you please tell us your order ID or the ASIN of the product?
It is better that you can tell us more details of how you operate the product, such as the input voltage/current, the wiring.
If you can, we sincerely hope that you can send us some photos to let us know the problem details.
You can send us an email to service at droking dot com to tell us the operating details and send the photos.
With your help, we can find a solution more quickly.
Beg your understanding and waiting for your reply.
Best regards