NOTES ON HANDLING AND REPLACEMENT OF THE LASER PICK-UP
1. Protection of the LD
Solder a part of the LD circuit to short-circuit. After connecting the circuit, remove the soldering form.
Precautions when handling the laser CD mechanism
2. Precautions when handling the laser CD mechanism
• Be careful not to expose the laser pick-up to dust.
• Do not leave the laser pick-up bare. Be sure to cover it.
• If dust adheres on the laser pick-up lens, blow it off with a blower brush.
• Do not apply shock to the laser pick-up.
• Do not watch the light of the laser pick-up.
3. Cautions on assembling and adjustment
• Be sure that the bench, jig, head of soldering iron (with ceramic) and measuring instruments are well
grounded.
• Workers who handle the laser pick-up must be grounded.
• The finished mechanism (prior to anchoring in the set) should be protected against static electricity
and dust.
The mechanism must be stored where abnormal external force is not applied.
• When carrying the finished mechanism, hold it by the chassis body.
• Do not use or store the mechanism where corrosive gas such as H2S, SO2, NO2 and CI2 or toxic gas
may be generated, or where substances especially organosilicon, cyanide, formalin and phenolic
materials exist. In particular, make sure that these substances which generate toxic gas do not exist in
the set. This may cause the motor not rotating.
4. Notes on Handling the Laser Pick-Up
• Measure the
q
RFEQO waveform of the DIGITAL PCB ASSY and check the amplitude level.
MEASURING METHOD AND WAVEFORMS
)
• If the amplitude level of the measured RFEQO waveform is between 0.4 and 1.1Vp-p, the pickup laser
is OK.
• Check the Iop (Laser drive current).
Check Iop in "
SPECIAL MODE
1-5-7. Displaying the laser current
• If the present Iop (the Laser current) value is "
80 mA
" or higher, replace the Traverse unit with a new
one.
• No mechanical adjustment is necessary after the replacement.
Protective soldering place for laser diode.
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
62