Have a problem with my phone speaker

@anmolkumar5002 if your speaker starts out okay but then the volume decreases could be an issues with the speaker or with the amplifier circuit on your main board. Start of by replacing the speaker (and the battery while you are at it) then re-evaluate. If a new speaker does not fix this you may need to find the schematics and boardview for your phone to check the amp circuitry. For that you may need somebody that has board level repair experience.

For the speaker replacement, and since iFixit does not yet have a specific guide for this, use the one from here It is written in Spanish so use a browser that will do the translating for you, if needed.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!