DELL 3501 MB la-k034p Sound issue

[ctebke]

Hello, I have dell 3501 MB la-k034p with Sound issue RED cross. No sound device in device manager. In BIOS diagnostic everything passes but no sound tone either in bios test. AUDIO chip is CS42l42 and 3.3v, 1.8v is present. Someone have any idea ? Thanks.

[ctebke]

Could be a BIOS problem ?

[mon2]

Install this driver:

https://www.dell.com/support/home/en...15-3501-laptop

[ctebke]

The problem is definitely hardware-related, but I can't figure out what's going on. There are over 40 pieces of the same NOTEBOOKS in my service. and I also have 2 correct identical ones. When I move the SSD with installed windows and drivers from the correct machine to these defective ones, a red cross just appears over the speaker. I see that many users have the same problem, but I don't see a concrete solution that someone has given.I also reflowed the processor on my JETRONICS-eco machine, but nothing changed...

[mon2]

Confirm that each board is with 100% same audio chip. Post clear pics of the working audio chip and also the non-working part. There must be a difference.

Is there a headphone connector? This can disable the speaker. Blow out the connector with compressed air. Does a headphone work?

[ctebke]

Definitely not a software problem. The same SSD with windows when placed on one board produces sound, when switched to this defective board there is no sound and no sound device at all in the device manager. Upgraded bios to latest version on both boards....

[mon2]

Confirm the voltage to ground of:

+1.8V_CS42L42
+1.8V_DVDD

[ctebke]

I have 1.8 on both resistor from picture above. Only where I can see deference is on R122 (CS8409_RST#), there is 0.0V and on working board there is 1.8V.

[mon2]

Good observation.

CS8409_RST#

The '#' suffix means the signal is ACTIVE_LOW type. That is, when this signal line is LOW = 0v, then the target part is being parked in the RESET state. It will not do anything with respect to sound or be configured by the host controller (these are slave devices). Respectively, this signal line must be '1' = logic high to continue operation. Start with checking if there is a pull-up resistor on this line that may be missing on the non-working board. Otherwise, the driving logic is not releasing this reset signal and therefore you have no audio.