820-2838 no audio

Djsp

Member
Hi in this card I encountered a strange problem, as OS X audio output gives me the headphone jack alone, I don't understand what the problem is and where to start, I just did the pram reset
 

2informaticos

Administrator
Staff member
You always get headphones, no speaker available?
Change LIO board; audio codec is there.

Very likely bad headphones connector.
You can try to clean it first, or replace.
 

Djsp

Member
I also tried to change the LIO
board to another is another flex but the result is the same.
The boot sound does
 
Last edited:

2informaticos

Administrator
Staff member
Boot sound (chime) is not related with audio codec.
However, LIO board is required.

Headphones/speakers detection is done by audio codec, in base of signals from audio connector; both placed on LIO board.

"You always get headphones, no speaker available?"
???
 

2informaticos

Administrator
Staff member
No reaction on System Prefferences -> Sound -> Output, when connect/disconnect headphones?

As I said, audio codec is in charge of detection.
The problem should be solved changing LIO board...
 

Djsp

Member
With the preferences open I tried to disconnect and reconnect but nothing remains unchanged this with two different lio tabs
 

2informaticos

Administrator
Staff member
Check the level of AUD_IP_PERIPHERAL_DET w/ and w/o headphones inserted.
Be sure to have good solders on its pin at J4700.
If no change, check R1781.
 

Djsp

Member
I measured AUD_IP_PERIPHERAL_DET with the 4.5V mi inserted headphones and with the headphones not inserted 3.0V but the system shows me only the earbuds as output
 

2informaticos

Administrator
Staff member
Did you try correct LIO board?
Changed the LIO flex too?

That signal is pulled-up to 3.3V; shouldn't get there 4.5V ever.
 

Djsp

Member
So I have to understand why when I insert the jack it reaches 4.5V which by the way must remain at 3.3 right?
 

2informaticos

Administrator
Staff member
Not sure about that.
On 820-3115, that signal is pulled-up to 4.5V; switches 0<->4.5V, depending if headphones (or SPDIF) is inserted.
Strange that on this Air board is pulled-up to 3.3V...

Audio codec expects another signal from the audio connector, to know if headphones, or speakers must be used as output.
 
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