View source for MacBook Pro A1708 No sound/audio, sound card is not showing up in the system repair

{{Repair Guide
|Device=MacBook Pro A1708
|Affects parts=Motherboard
|Needs equipment=multimeter, soldering iron, soldering station
|Type=Soldering
|Difficulty=3. Hard
}}
{{stub}}

==Problem description==
When A1708 is not playing audio and the audio device is not showing up in the system
[[File:Placeholder image.jpg|thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it!]]
==Symptoms==

*No audio out
*Sound card not showing up in the system

==Solution==
It could be a chipped off R2041 on the backside of the CPU, so no AUD_PWR_EN on L6361 and therefore only 0.3 V on L83_1V8 for the U6300 chip. Installed new resistor and sound card shows up.

You may want to check these four main ICs responsible for sound on the 820-00840/00875 boards U6200/6300/6400/6420. Compare diode mode reading with known good board in regard to these ICs. Also refer to schematic and check V<sub>IN</sub>, enables, data lines (U6400/6420 AUD_I2C_SDA/ AUD_I2C_SCL) etc. Check values of all resistors associated with these four ICs (refer to schematic for values)