Read Panasonic KX-DT521RU Service Manual Supplement online
3
1 Technical Descriptions
1.1.
Circuit Operations
Changed from Original Service Manual as section 4.2.1.
1.1.1.
LCD Circuit
LCD data are output from pin 66 of IC410 to LCD module.
LCD contrast is set by electronic volume in LCD module.
VCC33 (+3.3V) of the power supply voltage is doubled in the LCD module and used as LCD driving voltage (approx. 6.5V(KX-
DT521))
The driving voltage is observed between pin 12 (V0) and pin 13(XV0) of CN460.
The lighting of the backlight is controlled by Q460.
The power of the backlight is output from DOUT4V5 of IC410.
LCD contrast is set by electronic volume in LCD module.
VCC33 (+3.3V) of the power supply voltage is doubled in the LCD module and used as LCD driving voltage (approx. 6.5V(KX-
DT521))
The driving voltage is observed between pin 12 (V0) and pin 13(XV0) of CN460.
The lighting of the backlight is controlled by Q460.
The power of the backlight is output from DOUT4V5 of IC410.
Changed from Original Service Manual as section 4.2.2.
1.1.2.
Reset Circuit
IC410 (DCX81) is reset internally by itself when power is supplied.
Reset Signal is output from IC410 and input into IC300 (pin 1) ,CN460 (pin 5) and IC205 (pin 41).
Reset Signal is output from IC410 and input into IC300 (pin 1) ,CN460 (pin 5) and IC205 (pin 41).
D460
C460
L460
C462
C466
C464
C463
CN460
1
ESD-VSS
2
SCL
3
SDA
4
A0
5
/RES
6
/CS
7
VDD1
8
VD1
9
VSS
10
VDDA
11
VM
12
VO
13
XVO
14
VG
15
ESD-VSS
C467
DG
DG
VCC33
C461
C465
DG
DG
96
66
95
94
97
R435
R437
R436
R434
SPI_CLK
SPI_D0
LCD_A0
LCD_RS
LCD_CS0
7
LCD_BL
Q460
LED-
LED+
DCX81
IC410
25
C574
C575
LCD_PWR
DG
LCD Backlight
R463
C583
C582
DG
C584
DOUT4V5
EXGPIO10
GPIO18
GPIO17
GPIO16
GPIO15
GPIO19
3.3V
6
IC410
DCX81
R423
DG
C362
DG
1
IC300
RSTN
10
R424
DG
CN400
10
CN205
5
ASIC_RST
41
C243
DG
94
CN460
5
/RES
LCD_RS
IC205
VCC33
5
EXGPIO9
GPIO15
EXGPIO8
RSTN
VCC1
VCC2
VCC3
VCC3
VCC4
94
64
79
73
ASIC1
LCD
RESET
ASIC2
Main PCB
Ope PCB
RESETIC
DG
DG
DG
C429
R474
R473
C469
IC470
C468
4
1
3
2
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