820-4668 no output audio

Mac Tech

Member
It has a volume icon in the system, at the time of raising or lowering the volume it is gray.

I tried with another system and it has the same symptom.

change u6201 and the same.

pp4v5_audio_analog 4.45V

PP3V3_S0_AUDIO_ANALOG 3.3V

PP1V5_S0_AUDIO_DIG_FILT 1.5V

i'm thinking it may be some of the amps

but the voltages on the coils when powering up and listening to the sound of the PRAM

L6401 6.0v
L6400 6.0v

L6410 6.0v
L6411 6.0V

L6500 6.1V
L6501 6.1V

L6510 6.1V
L6511 6.1V

PP3V3_S0_AUDIO_SPKRAMP 3.3v

u6400
u6410
u6500
u6510

CODEC_SCL 3.29v
CODEC_SDA 3.29v

PP12V_S0_AUDIO_SPKRAMP
12V

SPKR_AMP_SD 00.2mv
SPKR_AMP_FAULT 3.13V
 

2informaticos

Administrator
Staff member
Is the audio codec recognized in the System Information?
Any input/output device appears on the Sound section into System Prefferences?
 

Mac Tech

Member
Yes.

Audio: Integrated microphone
integrated output

System preferences

Digital output - Digital optical output port
 

Mac Tech

Member
I did that diagnosis, disconnect the audio jack, it often shorts. That's why I discarded that possibility but still.

You don't need to be connected for the audio to work, do you?
 

2informaticos

Administrator
Staff member
The audio codec recognizes output device in base of conections made inside audio connector.
I don't have schematic of that audio board, to know what levels the codec expects.
Check on other iMac, if gets sound without that board connected...
 

Mac Tech

Member
RESOLVED! I changed the audio jack and the sound came back, I removed the one that is in good condition and the audio goes away.

It means that it must be connected for the audio on the speakers to work.

Thank you @2informaticos
 
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