Panasonic SA-PM21PC, Service Manual

Page: 8 / 92

The laser diode in the traverse deck (optical pickup) may break
down due to potential difference caused by static electricity of
clothes or human body.
So, be careful of electrostatic breakdown during repair of the
traverse deck (optical pickup).
l Handling of CD traverse deck (optical pickup)
1. Do not subject the traverse deck (optical pickup) to
static electricity as it is extremely sensitive to electrical
shock.
2. The short land between the No.4 (LD) and No.5 (GND)
pins on the flexible board (FFC) is shorted with a solder
build-up to prevent damage to the laser diode.
3. Take care not to apply excessive stress to the flexible
board (FFC board) (Fig 6.1).
4. Do not turn the variable resistor (laser power
adjustment). It has already been adjusted.
Fig 6.1
l Grounding for electrostatic breakdown prevention
1. Human body grounding (Fig 6.2)
Use the anti-static wrist strap to discharge the static
electricity from your body.
2. Work table grounding (Fig 6.2)
Put a conductive material (sheet) or steel sheet on the
area where the traverse deck (optical pickup) is placed,
and ground the sheet.
Caution :
The static electricity of your clothes will not be grounded
through the wrist strap. So, take care not to let your
clothes touch the traverse deck (optical pickup).
Fig 6.2
Caution when Replacing the Optical Pickup :
The traverse has a short point shorted with solder to protect
the laser diode against electrostatics breakdown. Be sure to
remove the solder from the short point before making
connections.
6 Handling Precautions For Traverse Deck
8
SA-PM21PC