CMT-U1BT, HCD-U1BT - Sony Audio Service Manual (repair manual). Page 4

4

•

Never reuse a disconnected chip component.

•

Notice that the minus side of a tantalum capacitor may be
damaged by heat.

•

Keep the temperature of the soldering iron around 270 

°

C

during repairing.

•

Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).

•

Be careful not to apply force on the conductor when soldering
or unsoldering.

Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.

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 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.

This appliance is classified as a
CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT
MARKING is located on the rear
exterior.

Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.

This mode is used to unable to take sample disc out of disc table in
the shop.
Procedure:

1. Press the

@/1

button to turn the power on.

2. Press the  

CD 

u 

 button to select “CD”.

3. Press two buttons of

x 

CANCEL

 

 and

Z

for 5 seconds.

4. The message “CD LOCKED” is displayed on the fluorescent

indicator tube and the disc slot is locked. (Even if pressing
the

Z

button, the message “CD LOCKED” is displayed on

the fluorescent indicator tube and the disc table is locked.)

5. To release from this mode, press two buttons of

x 

CANCEL

and

Z

for 5 seconds.

6. The message “CD UNLOCKED” is displayed on the fluores-

cent indicator tube and the disc table is unlocked.

*

•

The voltage and waveform of CSP (chip size package) cannot
be measured, because its lead layout is different from that of
conventional IC.

•

Lead layouts

New part of EEP ROM (IC6) on the USB board cannot be used.  Therefore,
if the mounted USB board (X-2149-040-1) is replaced, exchange new

EEP ROM (IC6) with that used before the replacement.

surface

Lead layout of
conventional IC

CSP (chip size package)

• Abbreviation

CND

: Canadian model

KR

: Korean model

Parts No.

AEP, UK models

2-683-402-0

[]

US model

2-683-403-0

[]

CND model

2-687-180-0

[]

KR model

2-892-323-0

[]