CDX-GT270MP, CDX-GT274MP, CDX-GT277ME, CDX-GT320MP - Sony Car Audio Service Manual (repair manual). Page 3

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
Never look into the laser diode emission from right above when 
checking it for adjustment. It is feared that you will lose your sight.

If the optical pick-up block is defective, please replace the whole 
optical pick-up block.
Never turn the semi-fi xed resistor located at the side of optical 
pick-up block.

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)

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.

The unit may not function properly if the connectors 
between the unit and the front panel are not clean. In order 
to prevent this, detach the front panel and clean the 
connectors with a cotton swab. Do not apply too much force. 
Otherwise, the connectors may be damaged. 

t For safety, turn off the ignition before cleaning the connectors, 
  and remove the key from the ignition switch.
t Never touch the connectors directly with yofingers or with 
  any metal device.

When the battery becomes weak, the range 
of the remote commander becomes shorter. 
Replace the battery with a new CR2025 
lithium battery. Use of any other battery 
may present a risk of fire or explosion.

Notes on the lithium battery
t Keep the lithium battery out of the reach of 

children. Should the battery be swallowed, 
immediately consult a doctor.

t Wipe the battery with a dry cloth to assure a 

good contact.

t Be sure to observe the correct polarity when 

installing the battery.

t Do not hold the battery with metallic tweezers, 

otherwise a short-circuit may occur.

WARNING
Battery may explode if mistreated.
Do not recharge, disassemble, or dispose 
of in fire.