NAD C 521i Service Manual page 11

PRECAUTIONS WHEN CHANGING LASER PICK-UP
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.
Caution:
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.
Protective soldering place
for laser diode
Soldering
Iron with
Ground
wire
Conductive Gum Mat
Ground Conductive
Wrist Band for Body
11
Ground Line
Less than
10 ohm