Panasonic KX-T7765X User manual

© 2008 Panasonic Communications Co., Ltd. All
rights reserved. Unauthorized copying and distribu-
tion is a violation of law.
ORDER NO. KMS0802455CE
Easa-Phone
Model No. KX-T7765X
(for Asia, Oceania, Middle Near Esat,
Africa and Latin America)

2
KX-T7765X
TABLE OF CONTENTS
PAGE PAGE
1 Safety Precautions -----------------------------------------------3
1.1. For Service Technicians ----------------------------------3
2Warning--------------------------------------------------------------4
2.1. About Lead Free Solder (PbF: Pb free) --------------4
3 Specifications ------------------------------------------------------5
4 Installation Instructions-----------------------------------------5
4.1. Installing the Doorphone ---------------------------------5
5 Disassembly and Assembly Instructions-----------------6
6 Miscellaneous ------------------------------------------------------7
6.1. Terminal Guide of the ICs, Transistors and
Diodes---------------------------------------------------------7
7 Schematic Diagram-----------------------------------------------8
7.1. Circuit Operation -------------------------------------------8
8 Printed Circuit Board --------------------------------------------8
8.1. Component View -------------------------------------------8
9 Appendix Information of Schematic Diagram -----------9
10 Exploded View and Replacement Parts List ----------- 10
10.1. Cabinet and electrical Parts Location --------------- 10
10.2. Accessories and Packing Materials ----------------- 11
10.3. Replacement Part List ---------------------------------- 12

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KX-T7765X
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.

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KX-T7765X
2Warning
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, ( 6 00°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.

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KX-T7765X
3 Specifications
4 Installation Instructions
4.1. Installing the Doorphone
1. Loosen the screw to separate the doorphone into 2 halves.
2. Pass the wires through the hole in the base cover, and attach the base cover to a wall using 2 screws.
Note
: when a doorphone plate has been fixed to the wall
: when you wish to install the doorphone directly onto the wall
3. Connect the wires to the screws located in the front cover.
4. Re-attach the 2 halves and re-insert the screw.
Dimensions (D x W x H): 27 mm x 98 mm x 130 mm
Weight: about 190g

6
KX-T7765X
5 Disassembly and Assembly Instructions
1. Remove 1 Screws (A).
2. Remove rear cabinet-B.
* Note: When tightening the screw(s), do not scratch cabinet wall with a
driver shaft.
3. Remove 3 Screws (B).
4. Remove rear cabinet-A.
5.Remove 1 Screws (C).
6. Remove P.C. Board.

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KX-T7765X
6 Miscellaneous
6.1. Terminal Guide of the ICs, Transistors and Diodes

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KX-T7765X
7 Schematic Diagram
7.1. Circuit Operation
1. Call circuit
Depressing switch S1 causes terminals 1 and 2 to be shorted through R7, therefore a call is detected at the doorphone
adaptor side.
2. Conversation
The transmited voice signal is sent to the doorphone adaptor via the following path.
Mic →Q1, 2 →(Mic amp.) →D1 →T1 →Doorphone adaptor.
The received voice signal is received at the SP via the terminal 1 →T1.
Note:
1. S1: Call switch.
8 Printed Circuit Board
8.1. Component View
R6
270
T
M(+)
M(-)
R
M1C C1
100
R1
2.2K
R2
2.2K
R4
150
C4
Q2Q1
10
16V
R8
150 R7
SP
S(-)
T1
4
D1
6
312
S(+)
1K
C6
1
50V
(NP)
S1
Call SW
C5
M0.047
C2
C3
M0.0047
R3
1K
R5
22K
50V 1
10V
KX-T7765X SCHEMATIC DIAGRAM
1.37V 2.75V
RECT
0.08V
MIC AMP 0.73VMIC AMP
0.69V
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KX-T7765X
9 Appendix Information of Schematic Diagram
Note:
1. DC voltage measurements are taken with an oscilloscope or a tester with a ground.
2. The schematic diagrams and circuit board may be modified at any time with the development of new technology.

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KX-T7765X
10 Exploded View and Replacement Parts List
10.1. Cabinet and electrical Parts Location