DAV-SB300, HCD-SB300 - Sony Audio Service Manual (repair manual). Page 5

5

The laser diode in the optical pick-up block may suffer electrostatic
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 flexible board is easily damaged and should be handled with
care.

The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.

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)

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 viscou-s (sticky, less prone to flow)

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.

The disc tray lock function for the antitheft of an demonstration
disc in the store is equipped.

Releasing Procedure :
Press two buttons of

A

and

x

simultaneously for five seconds.

The message “UNLOCKED” is displayed and the tray is unlocked.

When “LOCKED” is displayed, the tray lock is not released by turning
power on/off with the

I/

1

button.

When replacing the DMB07 board, since the adjustment value is
not set up correctly, “Drive Auto Adjustment” can’t be performed.
In this case, initialize Memory in the following procedures.

1. Set the test mode. (See page 24)
2. Press the [2] key of the remote commander, and set the “DRIVE

MANUAL OPERATION”. (See page 28)

3. Press the [6] key of the remote commander, and set the “2-6,

Memory Check”. (See page 30)

4. Press the [CLEAR] key of the remote commander, and initialize

Memory.

•

MODEL

PART No.

AEP, UK models

4-253-346-0[]

Russian model

4-253-346-1[]

Saudi Arabia model

4-253-346-2[]

Singapore model

4-253-346-3[]

Korean and Chinese models

4-253-346-4[]

Australian model

4-253-346-5[]

PART No.