Hello. I had a damaged microphone due to a high-pressure compressor working in production while blowing dirt. The phone is a Samsung Galaxy J7 Dual SIM 2017. I went to a private service to fix the fault. After the repair, it turned out that the phone loses its range and the phone's front camera is of poor quality. The one under the display. How to check the authenticity of parts and modules installed in the phone without disassembling it? Is there any possibility? I hope I haven't been cheated ..