A1466 820-00165-a No Sound

[flopper]

Got the board after water, more info from this post https://boards.rossmanngroup.com/threads/a1466-ppbus_g3h-at-4v.59468/#post-60661

It is working fine, but there is no sound, i got I/O board from 820-3437 and native one from 820-00165, when connect either of them to 820-3437 both works fine/audio present.
If connect both to 820-00165, either have no sound.

Any idea?

 

[2informaticos]

Missing headphone sound too?
Audio codec recognized in System Report?
Inspect J9500 pins for corrosion; HDA related...

 

[flopper]

audio codec is not recognised
headphone sound missing
j9500 pins are all soldered fine, no water near.

J9500 diode mode readings:
Pin47 0.465
Pin45 0.460
Pin43 0.413
Pin39 0.464

On donor board i am getting at Pin39 0.570

 

[2informaticos]

Compare all diode mode readings for HDA lines with working board.
3437 should have similar readings, I suppose.

Check if caps/resistors exist on these lines.

 

[flopper]

Check if caps/resistors exist on these lines.
[/QUOTE]

I checked all components and lines, all intact.

HDA_SDOUT R1313 33ohm
HDA_SDOUT_R R1921 1kohm
HDA_SYNC R1311 33ohm
HDA_BIT_CLK R1310 33ohm

J9500 diode mode readings:
Not working sound board:00165-a
Pin47 0.465
Pin45 0.460
Pin43 0.413
Pin39 0.464
Working sound board:3437-b
Pin47 0.505
Pin45 0.502
Pin43 0.455
Pin39 0.504

Can this tiny difference cause that issue?
Also i do not have 00165-a known good I/O board to check, only from 3437-b, is there a difference?

 

[2informaticos]

00165 board works with LIO from 3437 for sure; tested few days ago.
Probably viceversa valid too.

Not critical differences on the measurments...

 

[flopper]

any ideas?

 

[2informaticos]

Check first for corrosion on the MLB.
Probably someting more affected.

You may need to change LIO connector, J9500...

 

[flopper]

originally, corrosion was around u7701, u5000 and u7100.
I cleaned it all, is there something around SMC that is sound related, that i could have missed?

 

[2informaticos]

Is HDA_RST_L high?

Check the 4 resistors R1310-13.

 

[flopper]

I changed J9500, no luck.
i cannot measure HDA_RST_L when board is inside the housing, but when it is out it is 0v.
R1310 33ohm
R1311 33ohm
R1312 33ohm
R1313 33ohm

Noticed that outside the housing fan spins at max rpm, with one I/O board it is gradually starting to increase speed till maxes out, with other one it is straight away max speed, when place back in housing fan spins normally. Should it be like that?
I saw before how no sound issue appears if I/O board is faulty, fans spins at max and slow operating ( one of the sensors that is there does not read)
Could it be related?

 

[Kappy]

Hi Flopper I have the same problem as you and i'm following this thread to see if infomaticos can find a solution. Just to let you know that outside of the housing the fan will spin on full. It's normally to do with it not seeing the trackpad. So don't worry about that.

My 2 cents worth says that there's a problem with the PCH not sending out the signals to the audio controller but I could be wrong.

 

[flopper]

Hi Kappy! I was afraid that it might be cpu itself as there is no more things to check.

 

[2informaticos]

HDA_RST_L must be high.
Check it with both MLB and LIO board connected, out of the chassis.

 

[flopper]

HDA_RST_L is 0v out of the chassis when fan spins at max.

 

[2informaticos]

Fan max spins is caused by missing trackpad, normal issue out of chassis.
HDA_RST_L is not good, that's the reason of missing audio.
Check on the good board if is high only when LIO board connected, or even without LIO flex.

 

[flopper]

customer collected yesterday 3437-b. Will have to find board to check, will let you know.

 

[flopper]

i found one more 3437-b.
HDA_RST_L is 1.49v with LIO Connected with flex.
without flex HDA_RST_L is 0v on working board.

 

[2informaticos]

So the first board could still have a bad connection over LIO flex/connector.

 

[flopper]

i have tried 3 different Flex/LIO boards.
Replaced J9500
All HDA Pins reads ok, diode mode close to working board.
all i have left is to "just in case" replace all resistors on HDA lines and if thats not working thats mean its CPU?
Or hardwire 4 HDA lines from J9500 to Flex?