DOWNLOAD Panasonic KX-T7665RU (serv.man3) Service Manual ↓ Size: 1.47 MB | Pages: 41 in PDF or view online for FREE

5

T

E

L Jack

DX

DP Jack

JK2

ASIC

IC2

H/S Jack

TO

LCD

(CN5)

EEPROM

IC5

JK1

Q1

PDX

0

PDX

1

PDR

Data

Communication

T1

Q2

Q3

DDX

0

DDX

1

DDR

Q4

Q6

Q5

Data

Communication

Po

w

e

r

IC1

Q

21,

L21

D3V

A3

V

OS

R

OS

X

O

EP0

OCK

DX

DR

BCL

K

FS

LE

D

D32~

D42

Q31~

Q3

5

NROW0~

3

CLM0~

5

Ke

y

SW1~

3

2

Hook

SW

JK3

Reset

IC7

S

peaker

P

hone

IC3

3.3V     5.0V

IC8,D63

CODEC

IC4

CP

U

IC6

Tone

DB0~

7

ADR0~

5

W

E

N,REN,INTN

SCK,

DATA

LCD-D4~

7

E,W

,RS

SCL,SDA

X1

LE

D

D43

D44

MIC

CN2

SP

CN1

CN3-CN4

MAIN P. C. Board 

KX-T7665RU-B : BLOCK DIAGRAM

6

The key data is under the matrix control by 20 to 23(KEYOUT) and 28 to 35(KEYIN) of IC6.
The key information outputted from KEYOUT is inputted into KEYIN, when the key is pressed.

7

The LCD data is output from pins 52 to 58 of IC6.
LCD contrast adjustment is performed by the circuit composed of R603 and R604.
The contrast is determined only by the voltage level between pin 2 and pin 3 of CN5. Higher potential makes the contrast high.

CONTRAST

IC6 Pin 59

IC6 Pin19

HIGH

L

L

MIDDLE

Z

L

LOW

Z

Z

8

The lighting of the LED is controlled by pin 14 to 18 (Row) and pin 8 to 13 (Colum) of IC2.
The LED lights up in a dynamic lighting system.
The duty ratio is 1/8 (ON time 1.5ms).