Sony MEX-BT39UW Service Manual page 4

MEX-BT39UW/BT3900U/BT3950U
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.
TEST DISCS
Use following TEST DISC when this set confi rms the operation
and checks it.
Part No. Description
3-702-101-01 YEDS-18 (for CD)
4-225-203-01 PATD-012 (for CD)
NOTE FOR THE 20-PIN CONNECTOR (CN901)
Do not use alcohol to clean the 20-pin connector (CN901) connect-
ing the front panel with the main body.
Do not touch the connector directly with your bare hand. Poor con-
tact may be caused.
EXTENSION CABLE AND SERVICE POSITION
When repairing or servicing this set, connect the jig (extension
cable) as shown below.
• Connect the MAIN board (CN701) and the SERVO board
(CN401) with the extension cable (Part No. J-2502-076-1).
MAIN board
(CN701)
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NOTE FOR REPLACEMENT OF THE BT BOARD
When repairing, the complete BT board should be replaced since
any parts in the BT board cannot be repaired.
NOTE FOR REPLACEMENT OF THE SERVO BOARD
When repairing, the complete SERVO board should be replaced
since any parts in the SERVO board cannot be repaired.
NOTE FOR REPLACEMENT OF THE SWITCH BOARD
When SWITCH board is defective, exchange the MECHANICAL
BLOCK ASSY (P).
extension cable
(Part No. J-2502-076-1)
SERVO board
(CN401)