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Today at Atelier Kaz - Private NSX Enthusiast, ex-Honda R&D engineer with F1, Indy/CART background

Audio Head Unit Service 01

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Another owner sent in the Alpine audio head unit and the Bose speaker AMP.

The owner mentioned that the head unit sometimes worked and sometimes didn’t.
White noise when turning the volume knob (although this is more of contact cleaner required rather than circuit board issue).


So, tested the audio head unit on the bench first and indeed, there was almost no signal output from the unit.
If I turn the volume all the way up, I could get something but too low output.

There was white noise if I rapidly turn the volume up and down so needs cleaning.

Both Bose AMPs were tested on the bench and both of them were not the original ones fitted at the factory, they showed similar output level so should not be a big task for the refurbishment.


So, already managed to re-create the same issue on the bench, decided to open the head unit.










This head unit is rev.A so many modifications after the circuit board etching.
So many jumpers and additional components were installed afterwards.




And as expected, huge leakage from many caps.






Some sort of contamination/debris were observed around these OP-Amp so removed and checked this cap as well.




Some of the tracks were completely gone with no continuity.
Surprised that the unit was still working…..




My eyes…. Most of the tracks are less than 1mm so delicate touch required and I have to re-create the missing tracks using hard wires so not an easy task.
2 x hard wires in this photo.




Contact cleaner applied to the pot.










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Audio

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