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Text excerpt from page 21 (click to view)
5. CU-F117
5-1. Service Overview
5-1-1. Notes on Attaching the CN-2089 Board
B 2x4 (three) <Top View> CN-2089 board SONY logo Joint
Joint Place the PC board in the unit with the SONY logo facing you, and align the board so that the nub on the board fits into the small indentation on the unit.