LG G3 external speaker audio cuts out soon after boot
I'm having an elusive problem with my LG G3:
Soon after booting up, the external speaker's audio will cut out and pretty much stop completely. I say "pretty much" because it will occasionally and seemingly randomly start again for a few seconds here and there, then crackle and stop.
-Only external speaker is affected, not microphone or phone speaker
-Boots up with sound, then cuts out after a short time
-Possibly triggered by extended audio clips?
-Tapping on the phone has occasionally started / stopped the sound. This points to a hardware issue
-Problem seems replicable, but I am not missing the described "metallic-looking fabric" from the inside of my phone:
-My rear-facing camera also no longer works. Could be unrelated, but maybe not
-After the factory reset, I get errors from "Sprint ID" failing to download every boot. Cool stuff
Things I've tried:
-Clearing cache and data from various related apps
-Disabled USB routing from developer options
-Disabled power management in battery settings
-Disabled Google Voice
-Booted into Safe Mode (same symptoms)
-Tested via Sprint secret code (external speaker sometimes works, sometimes doesn't; rear-facing camera never does)
-Tested via Soundabout (doesn't work)
-Removed and reinstalled both external speaker and rear-facing camera
- Bending small copper speaker "springs" up towards the facing contacts
-Ordered new external speaker and rear-facing camera and installed those (twice, in the case of the camera)
This is a frustration, obviously... If anyone has any new ideas to fix it, or can at least tell me that my mobo is bunked so that I may move on, please respond!