Redmi 9A no speaker audio at random times

Manfred

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Apr 22, 2023
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I have the following problem with the speaker audio of my Xiaomi Redmi 9A:

- After a random time, typically between half an hour and several hours, the speaker audio stops working. In all apps, also ring tones, notification sounds, etc, all speaker sound fails. The CIT speaker test also fails while the problem is active.
- If I cover the proximity sensor, the phone switches to the ear speaker, and that one works normally. If I then uncover the proximity sensor, the phone switches back to the main speaker - and the speaker audio resumes working normally! While in the CIT test, covering and uncovering the proximity sensor does not restore speaker audio, but doing the "receiver" (ear speaker) test and then re-doing the speaker test will bring the speaker back to life.
- While the speaker audio is in the failure condition, there is a constant, very slight hiss coming from the speaker. Instead when the phone is working normally, there is no such hiss.
- After booting or rebooting the phone, it always works fine.

To me this looks like a software bug, that somehow hangs the audio system in such a way that the speaker amplifier is turned on and left on, while the audio signal is routed somewhere else, or simply dropped, leaving the speaker amplifier turned on and without an input signal. Doing anything that routes the audio to the ear speaker and then back to the main speaker clears the abnormal state.

I have read many reports about various audio problems with Xiaomi phones. Some of them seem to be the same problem I have, but most people fail to observe and describe the details.

I would love to know how to fix this. Roll-back? How, to which version? Some patch? After all, a phone that sometimes just won't ring when a call is coming in, is pretty useless!!! For the moment I'm making do by using the vibrator to alert me of incoming calls, but the vibrator isn't a full replacement of an audible ring, in many situations.

I have the MIUI Global version 12.5.6.0 Stable (RCDMIXM), and Android version 11 RP1A.200720.011.

I'm pretty sure that I'm not doing stupid things like having DND turned on, or the like. I don't use Bluetooth, nor plug-in headphones either. I did debloat the phone though, so MAYBE I did disable some app that I shouldn't have disabled, but I'm not aware of having done so. And I don't see how any app that I disabled could trigger such an audio problem, which seems to me to be a pretty low-level operating system bug. Anyway, if it is deemed useful, I can copy the entire list of factory-provided apps that I disabled, and the list of apps I installed.

The phone was purchased 7 months ago. I noticed the audio problem for sure only after installing WhatsApp about 10 days ago, but I think the problem was present before installing WhatsApp. I live in a fringe coverage area, so I wasn't surprised that sometimes my phone wouldn't ring, and I do remember that several times when playing a video there would be no audio, and after I did "something", like playing with the volume control, getting out of the video and back in, the audio would work again. Only yesterday I realized that what brings the speaker audio back to life is covering and uncovering the proximity sensor.

Any help is VERY welcome!

Manfred
 
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dangerousfen

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Aug 1, 2015
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It doesn't sound like an app issue but have you uninstalled WhatsApp to see if that fixes it?

I know it's a pain but a factory reset would be your best option.
 

Manfred

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No, I haven't yet uninstalled WhatsApp. I was considering doing that, but without much hope of nailing the problem. I suspect that WA might indeed be triggering the problem, for example when it sends audible notifications, but the culprit would still be the operating system, which seems to handle the audio hardware incorrectly, or have some other bug.

Factory reset is my last resort, before throwing this phone in the trash and buying one of a different brand. But I would have to keep the phone off-line until disabling all automatic updating, or it will automatically upgrade to the exact same version of Android and MIUI that it has now.

And I'm shying away from doing all the debloating, configuring and loading of useful apps, again! Particularly when the chances of success in that fixing the audio problem are slim.
 

Manfred

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Yesterday I turned off WhatsApp by force-stopping it and not re-opening it. The phone then worked normally for the rest of the day. So indeed the audio notifications from WhatsApp seem to be what triggers the problem. But being system-wide, the actual bug must be in the operating system.

Right now I'm testing with WhatsApp running, but with all its audio notifications turned off. So far the phone is working normally, but I need to let the test run for a few more hours before I can be reasonably sure.

Meanwhile I keep searching the web. It seems that the Android developers have had quite a few audio issues like the one affecting me. Such as these:



My best course of action might be rolling back the firmware, to whichever version works correctly. I just would like to know which one that is! So here is my plea: If you happen to have a Redmi 9A, and its audio system works fine, with WhatsApp notification sounds and all, then please let me know the exact versions of Android, kernel, and MIUI that work well for you!