MacBook Pro 2019 820-01700 Speaker amp issue.

[Gueric]

I have this MacBook Pro on my bench that I have already fixed, hard short on a SSD rail, but it also has another issue. the right speaker sound is either earrape, muffled or absent. Left one works perfect. I have tried replacing it, nothing changed so I'm pretty sure the issue is either motherboard related or maybe software but I doubt that.

I don't how to troubleshoot speakers. Any help would be very much appreciated.

A refurbisher and a repair shop have already been inside the laptop but I'm pretty sure none of them tried to do any soldering on the board.

[mon2]

Does the right side speaker work on the left side?

Not at my desk yet but hunt for the audio codec and amplifier linked to the right speaker. Confirm there is no damage in this region of the board.

[Gueric]

hey mon2. good to see you. I haven't tried that but I tried replacing both speakers just to make sure and it was still causing the same random issues with both speakers. For some reason now the left one works normal.

I also took a quick look at the 3 chips around the right speaker connector and nothing looks weird. no cracks, no weird colored caps, no corrosion.

[mon2]

Measure the voltage to ground of:

I2C_SPKRAMP_R_SCL
I2C_SPKRAMP_R_SDA

U6560 - PP1V8_G3S

U6560 may be defective and needs to be replaced.

[Gueric]

mon2 Hey. I can't probe the 2 I2C lines because the only component on those lines is a minuscule resistor inside the T2 metal shield. I probed PP1V8_G3S and it's exactly 1V8 as expected, stable.

How can I know which of the 3 speaker amp chips around the connector is defective ? do I go straight for U6560?

Also, one of my 2020 Intel MacBook Air board has the exact same speaker amp chip. Will it work if I harvest the chip from this board ?

Thanks

[Gueric]

Also forgot to add that, but we're talking about the right side speaker right ? U6560 is on the left side (maybe its the chip that manages all the other and I lack knowledge)

[Gueric]

ignore my previous message, I was distracted from work

[mon2]

Yes, to me U6560 is a suspect. The part is available on the market or from donor boards.

See here:

https://www.ebay.com/itm/335277989425

Assuming here that the actual speaker itself is not damaged. Do inspect the cone, etc for possible liquid or being torn damage. Other than this, perhaps the driving amp is defective which will be U6560.

[Gueric]

mon2 it would be very unlucky for both the original speaker and the remplacement one to be defective. I’ll replace all 3 chips just to make sure.

[Gueric]

Hey mon2 so I’ve replaced all 3 chips (not just U6560 just to make sure) and both speakers are now working. However a new issue appeared, causing both speakers to saturate a little in the highs, and a lot at high volume. What do you think could be the issue now ? The speakers themselves ? The other 3 chips ? I don’t know what to look for now