Nad C 541i COMPACT DISC PLAYER – Circuit Diagram

PRECAUTIONS FOR CHECKING BEAM EMISSION
The laser beam of this unit is focused on the reflecting surface of the objective lens in the optical system block.  Therefore, keep your eyes at least 12 inches (30 cm) away from the objective lens when the laser diode is ON.  (Operation Check Method for Laser Diode and Focus Search Function.)
When the POWER switch is turned ON after the chucking plate is removed, observe the objective lens and confirm that the following operations are performed properly.
(The optical system should be at the lead-in area position when it is checked at this time.)
(1) The laser should be at the innermost position after the chucking plate is removed.
(2) The diffused light of the laser beam can be seen when the POWER switch is turned ON.
(3) Vertical (up and down) movement of the objective lens (2 or 3 times) will take place.

Click on the pictures to magnify

Main board

MCU 

Display

RF amplifier

Amplifier

Power

Wiring

Exploded view

When removing the pick-up assembly, short circuit the PCB tracks on the optical block as show in the drawing in order to protect the pick-up before removal.

NOTE: Replacement pick-up assemblies are supplied with the PCB pattern already protected.

DO NOT REMOVE THE SHORT CIRCUITS UNTIL YOU HAVE FINISHED FITTING THE PICK-UP.

Laser diodes are extremely susceptible to damage from static electricity. Even if a static discharge does not ruin the diode, it can shorten its life or cause it to work improperly. When replacing the pick-up, use a conductive mat, a grounded soldering iron, and so on, to protect the laser diode from static damage.