I purchased three 10000mAh, 25W power banks (Model: EB-P3400). However, when I charge my phone using them, I notice hiss sound. This issue occurs with all three power banks, and they are brand new and unused.
As per your query, We request you kindly visit the service center for a physical inspection of your device. So that they can check the exact issue with the device and fix it at the earliest. The repair cost will be confirmed after the physical inspection of the device.
