DOWNLOAD Panasonic KX-TG7207UAJ / KX-TG7207UAM / KX-TG7207UAS / KX-TG7207UAT / KX-TG7208UAM / KX-TG7208UAS / KX-TG7208UAT / KX-TGA720UAJ / KX-TGA720UAM / KX-TGA720UAS / KX-TGA720UAT Service Manual ↓ Size: 2.32 MB | Pages: 88 in PDF or view online for FREE

4

• Repair service shall be provided in accordance with repair technology information such as service manual so as to pre-

vent 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.

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.

1. Danger of explosion if battery is incorrectly replaced.
2. Replace only with the same or equivalent type recommended by the manufacturer.
3. Dispose of used batteries according to the manufacture’s Instructions.

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 solder 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.

• PbF solder has a melting point that is 50 

°F ~ 70 °F (30 °C ~ 40 °C) higher than Pb solder. Please use a soldering iron with 

temperature control and adjust it to 700 

°F ± 20 °F (370 °C ± 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 the figure below).

5

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 manufacturer’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: 0.3 mm, 0.6 mm and 1.0 mm.

• Specifications are subject to change.

• Operation range: Up to 300 m outdoors, Up to 50 m indoors, depending on condition
• Analog telephone connection: Telephone Line

6

KX-TG7207/7208 BLOCK DIA

G

RAM 

(BASE UNIT)

Analog

Front

End

To TEL_LINE

A

B

CN1

Bridge

Rect

 D3 D3

Hook Switch

Q

4

,Q

5

Audio

Bell/Caller ID

Interface

Charge

Detector

CPU

59

54

61

52

60

56

55

BELL

HOOK

(Optional)

Off-Hook Line Voltage

64 ADCO

A/D

D/A

ADPCM

Codec Filter

DSP

Speech Encoding

BMC

Burst Encoding

RF

Interface

18

19

TXDA

RXDA

21

20

22

SYCL

SYDA

SYEN

ANT1

ANT2

RF Module

18

16

2

31

21

14

13

12

12

13

XTAL

X

1

10.368

MHz

EEPROM

SCL

SDA

6

5

7

To AC Adaptor

CN2

Limit

Resistor

CHARGE

CONTACT

VUNREG

3.3V

Reg.

IC

1

2.5V

Reg.

Q

9

1.8V

Reg.

Q

8

3.3 V

2.5 V

1.8 V

BBIC

Speech Decoding

Burst Decoding

7

Base Unit consists of the following ICs as shown in Block Diagram (Base Unit) (P.6).

• DECT BBIC (Base Band IC): IC7

- Handling all the audio, signal and data processing needed in a DECT base unit
- Controlling the DECT specific physical layer and radio section (Burst Module Controller section)
- ADPCM code filter for speech encoding and speech decoding (DSP section)
- Echo-cancellation and Echo-suppression (DSP section)
- Any tones (tone, sidetone, ringing tone, etc.) generation (DSP section)
- DTMF receiver (DSP section)
- Clock Generation for RF Module
- ADC, DAC, timer, and power control circuitry
- All interfaces (ex: RF module, EEPROM, LED, Analog Front End, etc.)

• RF Module: IC10

- PLL Oscillator
- Detector
- Compress/Expander
- First Mixer
- Amplifier for transmission and reception

• EEPROM: IC5

- Temporary operating parameters (for RF, etc.)

• Additionally,

- Power Supply Circuit (+3.3 V, +2.5 V, +1.8 V output)
- Crystal Circuit (10.368 MHz)
- Charge Circuit
- Telephone Line Interface Circuit