KX-T7665UA (serv.man3) - Panasonic PBX Service Manual (repair manual)

Model
KX-T7665UA (serv.man3)
Pages
41
Size
1.47 MB
Type
PDF
Document
Service Manual
Brand
Device
PBX / DIGITAL PROPRIETARY TELEPHONE
File
kx-t7665ua-sm3.pdf
Date

View Panasonic KX-T7665UA (serv.man3) Service Manual online

ORDER NO. KMS0803474CE
Digital Proprietary Telephone
Model No.
KX-T7665UA-B
Black Version
(for Ukraine)
2
KX-T7665UA-B
TABLE OF CONTENTS
PAGE
PAGE
1 Safety Precautions -----------------------------------------------3
1.1.  For Service Technicians ---------------------------------3
2 Warning --------------------------------------------------------------3
2.1. About Lead Free Solder (PbF: Pb free) --------------3
3 Specifications ------------------------------------------------------4
4 Technical Descriptions
------------------------------------------5
4.1. Block Diagram ----------------------------------------------5
4.2. Circuit Operations ------------------------------------------6
5 Location of Controls and Components------------------ 14
6 Installation Instructions
--------------------------------------- 15
6.1. Connection------------------------------------------------- 15
7 Troubleshooting Guide---------------------------------------- 16
7.1. No Operation ---------------------------------------------- 16
7.2. LCD Does Not Operate--------------------------------- 17
7.3. Handset Does Not Work-------------------------------- 18
7.4. Speaker-Phone Trouble -------------------------------- 19
7.5. DXDP-DPT Does Not Work --------------------------- 20
8 Disassembly and Assembly Instructions--------------- 21
8.1. Disassembly Instructions------------------------------- 21
9 Miscellaneous ---------------------------------------------------- 22
9.1. Terminal Guide of ICs, Transistors and Diodes--- 22
9.2. How To Replace a Flat Package IC ----------------- 23
10 Schematic Diagram--------------------------------------------- 24
10.1. ---------------------------------------------------------------- 24
10.2. Waveform -------------------------------------------------- 26
11 Printed Circuit Board ------------------------------------------ 30
11.1. Component View ----------------------------------------- 30
11.2. Bottom View ----------------------------------------------- 31
12 Appendix Information of Schematic Diagram --------- 32
13 Exploded View and Replacement Parts List 
----------- 33
13.1. IC Data------------------------------------------------------ 33
13.2. Cabinet and Electrical Parts Location--------------- 37
13.3. Accessories and Packing Materials ----------------- 38
13.4. Replacement Parts List --------------------------------- 39
3
KX-T7665UA-B
1 Safety Precautions
1.1.
 For Service Technicians
• Repair service shall be provided in accordance with repair technology information such as service manual so as to prevent fires,
injury or electric shock, which can be caused by improper repair work.
1. When repair services are provided, neither the products nor their parts or members shall be remodeled.
2. If a lead wire assembly is supplied as a repair part, the lead wire assembly shall be replaced.
3. FASTON terminals shall be plugged straight in and unplugged straight out.
• ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.
1. Cover plastic parts boxes with aluminum foil.
2. Ground the soldering irons.
3. Use a conductive mat on worktable.
4. Do not grasp IC or LSI pins with bare fingers.
2 Warning
2.1.
About Lead Free Solder (PbF: Pb free)
Note:
In the information below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that con-
tains lead.
We will use PbF when discussing the lead free solder used in our manufacturing process which is made from Tin, (Sn), Silver,
(Ag), and Copper, (Cu).
This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder. 
Caution
• PbF solder has a melting point that is 50
° ~ 70° F, (30° ~ 40°C) higher than Pb solder. Please use a soldering iron with tempera-
ture control and adjust it to 700
° ± 20° F, (370° ± 10°C). 
Exercise care while using higher temperature soldering irons.:
Do not heat the PCB for too long time in order to prevent solder splash or damage to the PCB.
• PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100
°F, (600°C).
• When applying PbF solder to double layered boards, please check the component side for excess which may flow onto the
opposite side (See figure, below).
2.1.1.
Suggested PbF Solder
There are several types of PbF solder available commercially. While this product is manufactured using Tin, Silver, and Copper,
(Sn+Ag+Cu), you can also use Tin and Copper, (Sn+Cu), or Tin, Zinc, and Bismuth, (Sn+Zn+Bi). Please check the manufac
turer's specific instructions for the melting points of their products and any precautions for using their product with other 
materials. 
The following lead free (PbF) solder wire sizes are recommended for service of this product: 0.3mm, 0.6mm and 1.0mm.
4
KX-T7665UA-B
3 Specifications
Design and specifications are subject to change without notice.
Station Loop Limit:
90 ohms
Calling Method:
2 pair wire
Jacks:
Handset Jack, TEL Jack
Dimensions:
Low Angle:
High Angle:
213 (D)mm 
× 177 (W)mm × 107 (H)mm
201 (D)mm 
× 177 (W)mm × 127 (H)mm
Weight:
0.7 kg
5
KX-T7665UA-B
4 Technical Descriptions
4.1.
Block Diagram
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-T7665UA-B : BLOCK DIAGRAM
6
KX-T7665UA-B
4.2.
Circuit Operations
4.2.1.
KEY Input Control Circuit
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
KX-T7665UA-B
4.2.2.
LCD Control Circuit
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.
LCD Contrast Control
CONTRAST
IC6 Pin 59
IC6 Pin19
HIGH
L
L
MIDDLE
Z
L
LOW
Z
Z
8
KX-T7665UA-B
4.2.3.
LED Circuit
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).
9
KX-T7665UA-B
4.2.4.
Reset Circuit
Reset Signal is outputted from IC7 and inputted into IC2,
IC3 and IC6 at the connection of TEL cord.
4.2.5.
Power Supply Circuit
This circuit converts the voltage supplied from PBX into the power supply voltage of +3.3V by IC1 (Switching Regulator IC).
Q22 and Q23 control the power supply circuit as below to turn IC1 on in low consumption current at starting up.
• Input Voltage approx. 26V or less 
→Q23 OFF →Q22 ON →IC1-pin 3 H →IC1 OFF
• Input Voltage approx. 26V or more 
→Q23 ON →Q22 OFF →IC1 ON
10
KX-T7665UA-B
4.2.6.
Data Communication
Function
The data communication circuit serves the following functions:
Information exchanger between PBX and proprietary telephone, key input information as well as data for the LED control, LCD
control, voice data, etc. This information is continuously exchanged at all times.
Circuit Operation
The data received from PBX is inputted to the comparator (pin 36) built in IC2 through Pulse Trans T1. The threshold voltage of
the comparator is determined by R101 to 103 and inputted to pin 37 and 35 of IC2.
The data to PBX is outputted from pin 38 and 39 of IC2, drives T1 by Transistor Q1 and transmitted.

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Here you can view online and download Panasonic KX-T7665UA (serv.man3) Service Manual in PDF. KX-T7665UA (serv.man3) service manual will guide through the process and help you recover, restore, fix, disassemble and repair Panasonic KX-T7665UA (serv.man3) PBX. Information contained in service manuals typically includes schematics / circuit diagrams, wiring diagrams, block diagrams, printed wiring boards, exploded views, parts list, disassembly / assembly, pcb.