Sony MHC-V41D Service Manual page 4

MHC-V41D
The SERVICING NOTES contains important information for servicing. Be sure to read this section before repairing the unit.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electro-
static break-down because of the potential difference generated by
the charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The fl exible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused
on the disc refl ective surface by the objective lens in the optical
pickup block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40 °C higher
than ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 °C.
Caution: The printed pattern (copper foil) may peel away if
the heated tip is applied for too long, so be careful!
• Strong viscosity
Unleaded solder is more viscous (sticky, less prone to fl ow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
• Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
4
SECTION 1
SERVICING NOTES
IMPORTANT NOTE OF PERFORMING THE OPERA-
TION CHECK
When performing the operation check of this unit, be sure to per-
form the operation check after checking that it is in the following
state.
• Heat sink is installed to MOTHER board
• Fan motor is connected to MOTHER board
Note: If turn the power on in the state that heat sink is not installed, there is
a possibility of damage.
Also, be sure to perform the operation check in the connect the fan
motor to the MOTHER board, and the fan motor is rotating state.
If it is necessary to perform the operation check with the heat sink
removed or the fan motor removed, set the volume to 10 or less and
perform the operation check within 1 minute.
MOTHER board
If "PROTECTX" (X is a number) APPEARS ON THE
DISPLAY, THEN "CHECK MANUAL" FLASHES ON
THE DISPLAY.
Immediately unplug the AC
power cord (mains lead), and
check if anything is blocking the
ventilation openings of the unit.
After you have checked and
found no problems, reconnect
the AC power cord (mains lead),
and turn on the system.
Protect Type Description:
Protect
No.
1
2
3
4
6
Contents
There is possibility of over current happen at speak-
er output.
or
Unusual heat up of AMP IC by improper assembly of
heat sink.
Defect of thermistor IC or charging circuit used by
SPM (Sound Pressure Management) system.
Power supply over current.
DC appears in SP terminal by defect of AMP IC.
Defect of DC FAN and DC FAN driver circuit.
fan motor
heat sink