Pro1X - problems with bottom=right loudspeaker - repair guide.

[claude0001 1,271]

@IMD seems to be absolutely right. The speaker failures occur only when /sys/class/power_supply/battery/voltage_now exceeds approx. 4100000 µV. This explains naturally why the phenomenon is more apparent when connected to a charger.

The question remains whether F(x)tec will indeed be able to fix this by a firmware update, or not ... 😞

Edited November 3, 2022 by claude0001

[IMD 3]

I doubt of something like over-voltage protection in speaker driver LSI.
By measuring of oscilloscope, I found it has a charge-pomp booster to make 2x vbat.
Output voltage may down when louder volume or battery discharged.

(But why only right speaker?)
(Parameters of the protection were not initialized only on right-speaker driver?)

I want schematics...

Edited November 4, 2022 by IMD

[claude0001 1,271]

3 hours ago, IMD said:

I want schematics...

Before we tear our phones apart any further it would be good to know whether F(x)tec are indeed aware of this problem and are planning a fix via firmware update. The (initial) October update can be interpreted in that way, but the wording is quite vague ...

[EskeRahn 5,399]

25 minutes ago, claude0001 said:

Before we tear our phones apart any further it would be good to know whether F(x)tec are indeed aware of this problem and are planning a fix via firmware update. The (initial) October update can be interpreted in that way, but the wording is quite vague ...

@Casey can you help us with info here?

[Casey 316]

1 hour ago, claude0001 said:

Before we tear our phones apart any further it would be good to know whether F(x)tec are indeed aware of this problem and are planning a fix via firmware update. The (initial) October update can be interpreted in that way, but the wording is quite vague ...

I've relayed this issue back to our dev team and they will look into it. I'll update here when there's progress. Thanks for bringing this up.

[brunoais 317]

Tried to reproduce and I still cannot.

Battery at 80% (4.108V), both when charging and not charging. Volume ranging from 10% to 60% (in intervals of 10) and for min 1 min in each.

I'm using OS V. 2.1.5 non-GMS.

[claude0001 1,271]

On 11/4/2022 at 10:56 PM, brunoais said:

I'm using OS V. 2.1.5 non-GMS.

2.1.5-GMS-less also here. And the problem is definitely there. So whatever fix they prepare, it's not in that ROM.

[claude0001 1,271]

On 11/3/2022 at 8:01 AM, IMD said:

I think it is not related with temp or charging state.

So I started playing around with my Pro1-X again.

After the device being shelved for ~1.5 weeks, the battery is now at 61% and /sys/class/power_supply/battery/voltage_now never exceeds 3870000 µV. In this state, I cannot reproduce the speaker issue!

So, maybe, it indeed occurs only on brand-new devices (and batteries) where the voltage exceeds 4.1 V significantly after charge ... ? This might explain why the problem goes away after some time of using the Pro1-X.

edit: Re-charging the Pro1-X now, to check whether the problem comes back with battery full.

Edited November 15, 2022 by claude0001

[claude0001 1,271]

So, the speaker issue is definitely improving.

With the battery fully charged (and /sys/class/power_supply/battery/voltage_now >~ 4100000 µV), the tapping sound reappeared sometimes while changing the volume of a playing youtube video, though not to the extend to make the video unwatchable.

Now, with the battery charge at 72% (/sys/class/power_supply/battery/voltage_now ~ 4000000 µV), I'm back to "cannot reproduce" ...

I am now quite confident that this problem will quickly go away with ageing of the battery, as others have observed, and I regret opening the Pro1-X for this (breaking a grand total of three of the tiny grounding springs surrounding the board in the process - do not insert your spudger to deep while opening the bottom shell!).