A2179 - No Audio

[iMuhtaseb]

this is a board of mine that's I've been trying to repair from time to time..

liquid damaged on right I/O.. after taking the I/O out and measure diodes and shorts on board I found everything OK except for SPKRAMP_INT_L readings were too high.. and sadly its associated with the T2 chip..

Days pass by and I'm now good with T2 chip.. so I've taken it out and put another one.. SPKRAMP_INT_L is reading OK now but no audio.. :| with known-good right I/O and known-good right I/O cable..

I've taken diode measurements.. and I've measured resistors for bad or blown resistors maybe somewhere.. And I could not find out the problem..

It might be an I2S line issue but sadly I do not own an oscilloscope :|

Other suggestions?

[mon2]

Check voltage and diode mode to ground at SPKRAMP_RESET_L.

[iMuhtaseb]

SPKRAMP_RESET_L
voltage 1.76v
resistance 3.99 kOhms
diode 0.428

[mon2]

So the I2S amplifier is not stuck in reset mode since the line is 1v8 and is powered by 1v8 so is parked out of reset.

Perhaps the audio IC is defective or has cat urine on the balls? If comfortable, consider to flux and reflow U6400.

It is relatively inexpensive but is a wlcsp package so not joy to replace.

https://www.mouser.ca/ProductDetail/...C24uRB3pOZ46UI

[iMuhtaseb]

omg you're a genius!

it worked.. I replaced it from another donor and it worked out..

why didn't I think of replacing it?! I went to replace a T2 but lazied out for replacing an amp IC.

Much appreciated it bro