Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

The Front AMP.

It’s been a while since last time I had to strip off so much
acid contaminated area on a single AMP.






Checked all four FETs and they were fine so no need to be replaced.

All caps replaced, powered up and quick bench testing to measure
the voltage at each pins on two ICs U1 and U2.

All came out within the spec including the gain and mute controller.






Applied hot meting glue, thermal compound and conformal coating and
placing back the silver metal case.






Each AMP is going through at least 2Hrs of final testing
using the actual Bose speaker.


So far, the testing is going well.




Message to the owner;

The silver metal case on the AMP is part of the heatsink for the four FETs.
The circuit board itself has extra copper patch where the FET body meets.

Therefore, on installation, it is important to screw down the metal case firmly
against the FET body to make good contact against the circuit board and
the FETs.




Hope to finish testing both AMPs today and return them next week.



Thank you for using my service.


Regards,
Kaz