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820-00239 Touch Bar not working when internal mic connected

A

ajdoc

Member
So Touch Bar was not working.
Disconnected flex and checked J5100.
Found short on on pin 20/21 PP1V8_DFR.

Removed board checked one more time and short gone.
Diode mode in correct value.

Turned on the MacBook and Touch Bar was working fine.
Did a restart is gone again.

Same short, disconnected all flexes and short is gone so connected all back.
Touch Bar was working fine and again after restart failed.

This time I disconnected flexes one by one and found when I disconnected microphone flex short gone.
Did 10 restarts with mic not connected and all works fine.
Diode mode on J6200 is correct and when there is short on J5100/20 all diode reading on J6200 are correct.

Replaced mic but still the same issue.
I can hear some short click sound from the speakers so maybe some issue with speaker amp?

How it can be linked? By 1.8V power rail?
Customer said it crash as well. When he leaving it in sleep overnight in the morning MacBook is turned off and battery is charged so it can be linked?

Any idea how to fix it?
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
Digital microphone connects with audio codec (U6200) through I2C bus.
You should try to change the chip.
 
A

ajdoc

Member
Yes, when J6200 disconnected all works fine (did 5 resarts)

Tested with known good Touch Bar and new flex which is connected to J4401.
With J6200 disconnected all good (did 5 restarts)
With J6200 connected but not fitted to palmrest and all good (did 5 restarts)
With J6200 connected to the flex which is fitted (already replaced just in case) in to palmrest and fail after first start.

So I removed mic flex from palmrest and connected it without fitting and all works fine so it looks like mic flex giving issue when is fitted to the palmrest.
I fitted mic flex and did insulations on components which are on the mic flex with kapton tape and all works fine from 2 days and after 50 restarts - I think it is solved.
 
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