Sharp R-350J Service Manual page 18

R-350J
Pin No. Signal I/O
72 COM13 OUT
73 COM14 OUT
74 COM15 OUT
75-102 OUT
SEG67-SEG40
103-142 OUT
SEG39-SEG0
143 COM7 OUT
144 COM6 OUT
PRECAUTIONS FOR USING LEAD-FREE SOLDER
1. Employing lead-free solder
The "Main PWB" of this model employs lead-free solder. This is indicated by the "LF" symbol printed on the PWB
and in the service manual. The suffix letter indicates the alloy type of the solder.
Example:
2. Using lead-free wire solder
When repairing a PWB with the "LF" symbol, only lead-free solder should be used. (Using normal tin/lead alloy solder
may result in cold soldered joints and damage to printed patterns.)
As the melting point of lead-free solder is approximately 40˚C higher than tin/lead alloy solder, it is recommend that
a dedicated bit is used, and that the iron temperature is adjusted accordingly.
3. Soldering
As the melting point of lead-free solder (Sn-Ag-Cu) is higher and has poorer wettability, (flow), to prevent damage
to the land of the PWB, extreme care should be taken not to leave the bit in contact with the PWB for an extended
period of time. Remove the bit as soon as a good flow is achieved. The high content of tin in lead free solder will cause
premature corrosion of the bit. To reduce wear on the bit, reduce the temperature or turn off the iron when it is not
required.
Leaving different types of solder on the bit will cause contamination of the different alloys, which will alter their
characteristics, making good soldering more difficult. It will be necessary to clean and replace bits more often when
using lead-free solder. To reduce bit wear, care should be taken to clean the bit thoroughly after each use.
Common data signal : COM3. Connected to LCD signal COM3.
Common data signal : COM2. Connected to LCD signal COM2.
Common data signal : COM1. Connected to LCD signal COM1.
Terminal not used.
Segment data signal.
Connected to LCD.
The relation between signals and LCD are as follows:
LSI signal LCD
(Pin No.) segment
SEG 39 (103) .......... SEG 1
SEG 38 (104) .......... SEG 2
SEG 37 (105) .......... SEG 3
SEG 36 (106) .......... SEG 4
SEG 35 (107) .......... SEG 5
SEG 34 (108) .......... SEG 6
SEG 33 (109) .......... SEG 7
SEG 32 (110) .......... SEG 8
SEG 31 (111) .......... SEG 9
SEG 30 (112) .......... SEG 10
SEG 29 (113) .......... SEG 11
SEG 28 (114) .......... SEG 12
SEG 27 (115) .......... SEG 13
SEG 26 (116) .......... SEG 14
Common data signal : COM9. Connected to LCD signal COM9.
Common data signal : COM10.
Sn-Ag-Cu
Indicates lead-free solder of tin, silver and copper.
Description
LSI signal LCD
(Pin No.) segment
SEG 25 (117) .......... SEG 15
SEG 24 (118) .......... SEG 16
SEG 23 (119) .......... SEG 17
SEG 22 (120) .......... SEG 18
SEG 21 (121) .......... SEG 19
SEG 20 (122) .......... SEG 20
SEG 19 (123) .......... SEG 21
SEG 18 (124) .......... SEG 22
SEG 17 (125) .......... SEG 23
SEG 16 (126) .......... SEG 24
SEG 15 (127) .......... SEG 25
SEG 14 (128) .......... SEG 26
SEG 13 (129) .......... SEG 27
Connected to LCD signal COM10.
16
LSI signal LCD
(Pin No.) segment
SEG 12 (130) ........ SEG 28
SEG 11 (131) ........ SEG 29
SEG 10 (132) ........ SEG 30
SEG 9 (133) ........ SEG 31
SEG 8 (134) ........ SEG 32
SEG 7 (135) ........ SEG 33
SEG 6 (136) ........ SEG 34
SEG 5 (137) ........ SEG 35
SEG 4 (138) ........ SEG 36
SEG 3 (139) ........ SEG 37
SEG 2 (140) ........ SEG 38
SEG 1 (141) ........ SEG 39
SEG 0 (142) ........ SEG 40