SPEAKER
MIC
HANDSET
JK2
Amp
OHCA
SP-Phone
IC
OHCA
CODEC
GATE
ARRAY
TONE
DETECT
CPU
LCD
CONT
CN2
KEY
LCD p.c.board
LCD
PANEL
T7456
(24x6)
LCD
CONTROLER
LCD
DRIVER
KEY
x3
PI
NI
C0~C5
R0~R5
4MHz
CK2K
SW301
JOG SW
3AP
2AP
LED
DRIVING
Q3~Q12
Q13~Q18
LED
D100~D117, D130
+5V
RESET
HOOK SW
x2
12.288
MHz
x1
+5V
Main p.c.board
DATA
COMMUNI-
CATION
DC-DC
CONVERTER
T1
POWER REGULATOR
D1
+ ~
-
~
+5V
-
5V
16.384
MHz
RX
1AP
TX
RX
TEL JACK
JK1
PBX
TX
INT,
RD,WT,
A0,A1,
D0~D3
INT,
RD,WT,ALE,
D5~D7
RR,RD,RB
RR,RD,RB
CODEC (D A/A D)
SP-Phone CIRCUIT
HANDSET CIRCUIT
TONE GENELATOR
DPITS
communi
-cation
LED
Control
JOG SW
Control
Summary of Contents for KX-T7456 - Digital 24 Button Speakerphone Display
Page 4: ...4 DISASSEMBLY INSTRUCTIONS 4 1 HOW TO REMOVE THE LOWER CABINET Procedure 1 4 ...
Page 8: ...5 IC DATA 5 1 IC1 8 ...
Page 11: ...11 ...
Page 15: ...15 ...
Page 20: ...7 4 DATA COMMUNICATION CIRCUIT 1 Function 20 ...
Page 24: ...The reset signal is negledted 24 ...
Page 29: ...8 TROUBLESHOOTING GUIDE 8 1 NO OPERATION 8 2 THE LCD DOES NOT OPERATE 29 ...
Page 31: ...8 5 SPEAKER PHONE TROUBLE 8 6 TONE DIAL TROUBLE 8 7 TROUBLE OF OHCA 31 ...
Page 32: ...8 8 HANDSET TROUBLE 9 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 32 ...
Page 36: ...12 CABINET AND ELECTRICAL PARTS LOCATION 13 ACCESSORIES AND PACKING MATERIALS 36 ...
Page 49: ...33 37 34 35 36 25 32 ...
Page 55: ...SW301 CN301 1 2 3 ...
Page 57: ...1 5 2 6 3 7 4 8 ...
Page 58: ...9 13 10 14 11 15 12 16 ...
Page 59: ...17 21 18 22 19 23 20 24 ...