Panasonic KX-TCA256X User manual

© 2006 Panasonic Communications Co., Ltd. All
rights reserved. Unauthorized copying and distribu-
tion is a violation of law.
ORDER NO. KMS0611302CE
DECT Portable Station
KX-TCA256X
(for Taiwan and Mexico)

2
KX-TCA256X
TABLE OF CONTENTS
PAGE PAGE
1 Safety Precautions -----------------------------------------------3
1.1. For Service Technicians ----------------------------------3
1.2. Disposal Cautions------------------------------------------3
2Warning--------------------------------------------------------------4
2.1. About Lead Free Solder (PbF: Pb free) --------------4
2.2. Battery Caution ---------------------------------------------4
3 Specifications ------------------------------------------------------5
4 Technical Descriptions------------------------------------------6
4.1. Block Diagram (Handset) --------------------------------6
4.2. Circuit Operation (Handset) -----------------------------7
4.3. Block Diagram (RF Unit) ---------------------------------8
4.4. Circuit Operation (RF Unit) ------------------------------9
4.5. Signal Route-------------------------------------------------9
5 Location of Controls and Components------------------ 10
5.1. Location of Controls (Handset) ----------------------- 10
6 Installation Instructions--------------------------------------- 11
6.1. Connection------------------------------------------------- 11
6.2. Battery ------------------------------------------------------ 11
7 Operation Instructions ---------------------------------------- 13
7.1. Soft Key Display ------------------------------------------ 13
7.2. Settings Menu Chart (Handset) ---------------------- 14
7.3. Key Lock---------------------------------------------------- 15
7.4. Selecting the Display Language---------------------- 15
7.5. DISPLAY --------------------------------------------------- 15
8 Troubleshooting Guide---------------------------------------- 22
8.1. Check Power (Handset) -------------------------------- 23
8.2. RF Unit------------------------------------------------------ 23
8.3. Check Battery Charge (Handset) -------------------- 24
8.4. Check Link (Handset) ----------------------------------- 26
8.5. Check Handset Transmission------------------------- 27
8.6. Check Handset Reception ----------------------------- 27
8.7. Bell Reception (Handset) ------------------------------ 27
9 Service Fixture & Tools --------------------------------------- 28
10 Disassembly and Assembly Instructions--------------- 29
10.1. Handset----------------------------------------------------- 29
10.2. Charger Unit ----------------------------------------------- 30
11 Measurements and Adjustments -------------------------- 31
11.1. Check Procedure (Handset)--------------------------- 31
11.2. Adjustments (Handset and Charger Unit)---------- 36
11.3. RF Specification (Handset) ---------------------------- 41
11.4. How to Check the Handset Speaker ---------------- 42
11.5. How to Check the Handset Receiver --------------- 42
11.6. Frequency Table (MHz)--------------------------------- 43
11.7. How To Replace a Flat Package IC ----------------- 44
12 Schematic Diagram--------------------------------------------- 45
12.1. For Schematic Diagram -------------------------------- 45
12.2. Schematic Diagram (Handset)------------------------ 46
12.3. Handset (RF Unit)---------------------------------------- 48
12.4. Charger Unit ----------------------------------------------- 49
13 Printed Circuit Board ------------------------------------------ 50
13.1. Handset----------------------------------------------------- 50
13.2. Charger Unit ----------------------------------------------- 51
14 Appendix Information of Schematic Diagram --------- 52
14.1. CPU Data (Handset) ------------------------------------ 52
14.2. Terminal Guide of the ICs, Transistors and
Diodes------------------------------------------------------- 54
15 Exploded View and Replacement Parts List ----------- 55
15.1. Cabinet and electrical Parts Location
(Handset) -------------------------------------------------- 55
15.2. Accessories and Packing Materials----------------- 57
15.3. Replacement Part List---------------------------------- 58

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KX-TCA256X
1 Safety Precautions
1.1. For Service Technicians
ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.
1. Cover the plastic parts boxes with aluminum foil.
2. Ground the soldering irons.
3. Use a conductive mat on the worktable.
4. Do not touch IC or LSI pins with bare fingers.
1.2. Disposal Cautions
1.2.1. Information on Disposal for Users of Waste Electrical & Electronic Equipment (pri-
vate households)
This symbol on the products and/or accompanying documents means that used electrical and electronic products should not
be mixed with general household waste.
For proper treatment, recovery and recycling, please take these products to designated collection points, where they will be
accepted on a free of charge basis. Alternatively, in some countries you may be able to return your products to your local retailer
upon the purchase of an equivalent new product.
Disposing of this product correctly will help to save valuable resources and prevent any potential negative effects on human
health and the environment which could otherwise arise from inappropriate waste handling. Please contact your local authority
for further details of your nearest designated collection point. Penalties may be applicable for incorrect disposal of this waste,
in accordance with national legislation.
1.2.2. For business users in the European Union
If you wish to discard electrical and electronic equipment, please contact your dealer or supplier for further information.
1.2.3. Information on Disposal in other Countries outside the European Union
This symbol is only valid in the European Union.
If you wish to discard this product, please contact your local authorities or dealer and ask for the correct method of disposal.

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KX-TCA256X
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, (3 0°~ 40°C) higher than Pb solder. Please use a soldering iron with tempera-
ture control and adjust it to 700°± 20°F, ( 37 0 °± 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.
2.2. Battery Caution
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.

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KX-TCA256X
3 Specifications
Handset Charger Unit
Standard: DECT= (Digital Enhanced Cordless Telecommunications)
GAP= (Generic Access Profile)
Power Source: Rechargeable Ni-MH battery AC Adaptor
Power Consumption Standby: Approx. 270W
Maximum: Approx. 270W
Number of Channels: 120 Duplex Channels
Frequency Range: 1.88GHz to 1.9GHz
Duplex Procedure: TDMA (Time Division Multiple Access)
Battery Life, Handset (if batteries are fully charged): Stand-by: Up to 120 hours (Ni-MH)
Talk: Up to 17 Hours (Ni-MH)
Channel Spacing: 1728kHz
Bit rate Spacing: 1152kbit/s
Operating Conditions: 5~40 °C, 20~80% relative air humidity (dry)
Modulation: GFSK= (Gaussian Frequency Shift Keying)
RF Transmission Power: approx. 250mW
Voice Coding: ADPCM 32 kbit/s
Operation Range: Up to 300 m outdoors, Up to 50 m indoors
Dimensions (D x W x L): 123 mm x 45 mm x 22 mm 78 mm x 78 mm x 59 mm
Weight: about 120g about 108g

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KX-TCA256X
4 Technical Descriptions
4.1. Block Diagram (Handset)
12
CPU
IC201
BBIC
A/D
D/A
Analog
Front
End
Speech
Encoding
Speech
Decoding
DSP
ADPCM
Codec
Filter
BMC
RF
Interface
MIC
SYRI
RSSI
SYEN
RXDA
TXDA
19
17
16
9
20
To RF
Block
BATTERY
TERMINAL
BATTERY +
CHARGE
CIRCUIT CHARGE
CHARGE DETECT
CHARGE
CONTACTS
CHARGE
3.6V
VBAT2
11
XTAL
10.368
BATTERY
MHz
KEYPAD
COLUMNS
ROWS
LCD
96X64
dot
ON SWITCH
55
54
53
64
KX-TCA256X BLOCK DIAGRAM (HANDSET)
47
46
63
62
49 24
23 SCLK
30 CLK
21 SRQ
20 ERQ
31
AOUT
39
41
33,34,37
4
1
50
RECEIVER
SPEAKER
69
70
68
76
28~32, 40
35, 36, 37, 38
Burst
Encoding
Burst
Decoding
+
CHARGE
D102
49
RESET
CS 2
AO
SI
SCL
AMPLIFIER
IC401
Headset
JACK
SP_AMP Control
3
MIDI
IC301
LOGIC IC
LCD-BACK LIGHT
(Blue)
KEY-BACK LIGHT
(Green)
SP-PHONE LED
(Red)
CHARGE LED
(Red and Green)
6.00MHz
IC303
Q101,Q102,Q103
R7,R101,R103,R117
Q104
Q105
X100
2.75V
2.7V 1.85V
21 SYDA
22 SYCL
BATTERY -
X101
BATT
VIB

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KX-TCA256X
4.2. Circuit Operation (Handset)
4.2.1. Outline
Handset consists of the following ICs as shown in Block Diagram (Handset) (P.6).
• DECT BBIC (Base Band IC): IC201
- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter, LCD)
Include EEPROM and Flash memory
EEPROM stores the temporary operating parameters (for RF, etc.)
• AMP: IC401
- Single OP_AMP for SP
• MIDI: IC301
- 16-Tone 32-Poly PCM Sound Generator
- Port (LED direct driver with PWM)
•RFBlock
-IC601
PLL Oscillator
Detector
Compress/Expander
Amplifier for reception
-IC602
Amplifier for transmission
Power control
4.2.2. Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(3.5V~4.2V: Battery+) →Q104 (1.8V)
→Q105 (2.7V)
The Reset signal generates IC201 (78) and 1.8V.
4.2.3. Charge Circuit
Circuit Operation:
When charging the handset on the charger, the charge current is as follows;
DC+(9V~10V) →IC601(6) →IC601(2) →L601 →JT601(Charger) →JT101(Handset) →L101 →Q101→D102 →BAT-
TERY+... Battery... BATTERY- →R115 →GND →L102→JT102(Handset) →JT602(Charger) →R616, R617, R618, R619 →
GND →DC-(GND)
In this way, the BBIC on Handset detects the fact that the battery is charged.
The charge current is controlled by switching Q101 of Handset.
4.2.4. Battery Low/Power Down Detector
Circuit Operation:
"Battery Low" and "Power Down" are detected by BBIC which check the voltage from battery.
The detected voltage is as follows;
• Battery Low
Battery voltage: V(Batt) 3.5V ± 50mV
The BBIC detects this level and " " starts flashing.
• Power Down
Battery voltage: V(Batt) 3.3V ± 50mV
The BBIC detects this level and power down.
4.2.5. Speakerphone and Headset Jack
The hands-free loudspeaker at CN401(1) and CN401(2) is used to generate the ring alarm. IC401 is used to switch off the tele-
phone loudspeaker and is used to amplify the signal to drive the hands-free loudspeaker. They are selected using the SP_AMP
line from pin 70 of the BBIC. 2.5mm headset jack is also available.

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KX-TCA256X
4.3. Block Diagram (RF Unit)
2
:R
CHP
:N/A
PLL & Control logic
VCO
PD
Low IF bandpass filter
LNA Mixer
IC601
RSSI
KX-TCA256X (RF UNIT)
RXDA
SYCL SYDA SYEN
FIL601 D601
RXDSG
Loop filter
TXDA
SYRI
PAON
RXON
PSEL
BATT
Voltage regulator
Voltage regulator
To CPU Block
To CPU Block
IC602
Antenna
S&H
Demodulator
:32/33
VCCS
VCC1
VCC
Voltage regulator
IC603
VCC2

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KX-TCA256X
4.4. Circuit Operation (RF Unit)
To measure the charge-current, R616-619 transfer the current to a voltage.
When the charge-current is 200mA, the voltage is 0.05V.
IC602 amplifies the voltage to 24.5time, then the output voltage is 24.5X0.05=1.225V.
IC601 is DC/DC convertor. This IC adjusts CII to 1.25V.
Then the charge current is adjusted to 204mA.
When charging is completed, the BBIC (IC201) of the portable station set the Q103-Base to "High", then Q102 is turned off. As
a result, the charging current is stopped.
4.5. Signal Route
To measure the charge-current,R616-619 transfer the current to a voltage.
When the charge-current is 200mA,the voltage is 0.05V.
IC602 amplifies the voltage to 24.5time,then the output voltage is 24.5X0.05=1.225V.
IC601 is DC/DC convertor.This IC adjusts CII to 1.25V.
Then the charge current is adjusted to 204mA.
When charging is completed, the BBIC (IC201) of the portable station set the Q103-Base to "High", then Q102 is turned off. As
a result, the charging current is stopped.

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KX-TCA256X
5 Location of Controls and Components
5.1. Location of Controls (Handset)

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KX-TCA256X
6 Installation Instructions
6.1. Connection
• Use only the included Panasonic AC adaptor (KX-TCA1-2).
6.2. Battery
6.2.1. Battery Installation
Insert the batteries as shown. Close the cover as indicated by the arrow.
6.2.2. Battery Charge
At the time of shipment, the battery is not charged.
Please charge the battery for more than 5.5 hours before initial use.
• When the battery has been completely charged, the charge indicator will change from red to green.
• It is normal for the PS and charger to feel warm while the battery is charging.
• Keep devices sensitive to magnetic fields away from the charger.

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KX-TCA256X
6.2.3. Battery Information
After your Panasonic battery is fully charged [at 25°C]:
• Battery charge may be shortened depending on usage conditions and ambient temperature.
• The batteries cannot be overcharged.
• The batteries will drain even while the unit is "OFF".
• The PS can receive calls while charging.
• Battery consumption increases when the PS is used out of range. If " " flashes, power off the PS.
•Clean the handset and the charger contacts with a soft, dry cloth once a month. Clean more often if the unit is subject to
grease, dust or high humidity. Otherwise the battery may not charge properly.
• Read "Important Notice Concerning the Correct Use and Charging of Ni-MH Batteries."
6.2.4. Low Battery Warning
The batteries needs to be charged when " " flashes or the alarm sounds every one minute during a conversation.*
* If the low battery warning occurs during a conversation, you can continue the call for a few minutes, then the call will be discon-
nected automatically.
6.2.5. Replacing the Batteries
If " "flashes after a few telephone calls even when the batteries have been fully charged, it is time to replace the batteries
with new ones.
1. Turn the power off to prevent memory loss.
2. Press the notch on the cover firmly and slide it as indicated by the arrow.
3. Open the cover and replace the battery.
4. Close the cover and charge the handset for more than 5.5 hours.
Please replace with Panasonic battery only.
• Please order part number N4HHGMB00007.
If you replace the battery before the low battery warning appears, the battery strength icon may display an inaccurate reading. In
this case, use the PS as normal with the new battery installed. When the low battery warning is displayed, charge the battery for
more than 5.5 hours. The battery strength icon will then display a correct reading.
Operation Operating Time
While in use (TALK) 17 hrs approx.
While not in use (Standby) 270 hrs approx.

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KX-TCA256X
7 Operation Instructions
7.1. Soft Key Display
Icons and information shown on the display will vary depending on the state of use. To select an item shown on the display, press
the corresponding soft buttons.

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KX-TCA256X
7.2. Settings Menu Chart (Handset)

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KX-TCA256X
7.3. Key Lock
You can lock the dialling buttons while the PS is in idle status.
7.4. Selecting the Display Language
• When set to "Auto", the language settings of the Business Telephone System will be used automatically.
• The display language of both the PS and Business Telephone System can be selected, and both should be set to the same lan-
guage. Refer to the Business Telephone System User manual for more details.
7.5. DISPLAY
7.5.1. Display Icons

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KX-TCA256X
7.5.2. Main Menu-while in standby mode
7.5.3. Sub menu-while in off-hook/during a conversation
7.5.4. PBX Feature Menu

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KX-TCA256X
7.5.5. Troubleshooting
7.5.6. Power ON/OFF
7.5.7. Using the Handset Phone book

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KX-TCA256X
7.5.8. Using the PBX System Phone book
7.5.9. Using the PBX Extension Phone book
7.5.10. Character Mode Table

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KX-TCA256X
7.5.11. Editing
• * The valid digits are "0" through "9", " ", " ", PAUSE.
• To change a character or digit, move the joystick to highlight it, press to delete it, then enter the new character or digit.
• To clear an entire line, press and hold .
• To move the cursor to the left or right, move the joystick or , respectively.
7.5.12. Deleting
7.5.13. Storing an item in the Handset Phone book
7.5.13.1. Using the Outgoing Call Log

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KX-TCA256X
7.5.14. Using the Incoming Call Log
7.5.15. Using the Incoming Call Log Group
7.5.16. Using the PBX System Phone book
• * Press to confirm each entries.
• When storing an outside phone number, the line access number will be stored automatically. The line access number must be
identical to the PS's "Line Access CD" setting (Call Option).