This document is just what I was looking for, it´s very useful, it contains adjustment procedures for the final stage of the power amp and also
has a complete wiring diagram and description of the main semiconductors used in the design.
Text excerpt from page 73 (click to view)
UX-P410TH/FO-P610TH/NX-P160TH 3. Shading paper
The white and black basis is applied to remember the shading waveform. Be sure to perform this operation when replacing the battery or replacing the control PWB. Execute in the shading mode of DIAG mode.
SHADING WAVE MEMORY STANDARD PAPER (PSHEZ3579SCZZ)