Panasonic KX-TG8421EB Service Manual
  1. Manuals
  2. Brands
  3. Panasonic Manuals
  4. Answering Machine
  5. KX-TG8421EB
  6. Service manual

Panasonic KX-TG8421EB Service Manual

Digital cordless answering system
Hide thumbs
Table of Contents

Advertisement

Quick Links

Telephone Equipment
KX-TG8421EB
Model No.
KX-TG8421EM
KX-TG8421EN
KX-TG8422EB
KX-TG8422EM
KX-TG8422EN
KX-TG8423EB
KX-TG8423EM
KX-TG8423EN
KX-TG8424EB
KX-TG8424EM
KX-TG8424EN
KX-TGA840EB
KX-TGA840EM
KX-TGA840EN
Digital Cordless Answering System
B:Black Version
M:Metallic Grey Version
N:Platinum Silver Version
(for United Kingdom)
© Panasonic Communications Co., Ltd. 2009.
Unauthorized copying and distribution is a viola-
tion of law.
ORDER NO. KM40901797CE

Advertisement

Table of Contents
loading

Related Manuals for Panasonic KX-TG8421EB

Summary of Contents for Panasonic KX-TG8421EB

  • Page 1 KX-TG8423EB KX-TG8423EM KX-TG8423EN KX-TG8424EB KX-TG8424EM KX-TG8424EN KX-TGA840EB KX-TGA840EM KX-TGA840EN Digital Cordless Answering System B:Black Version M:Metallic Grey Version N:Platinum Silver Version (for United Kingdom) © Panasonic Communications Co., Ltd. 2009. Unauthorized copying and distribution is a viola- tion of law.
  • Page 2 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E...

  • Page 3: Table Of Contents

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E TABLE OF CONTENTS PAGE PAGE 1 Safety Precautions----------------------------------------------- 4 13.1. For Schematic Diagram -------------------------------- 82 1.1. For Service Technicians --------------------------------- 4 13.2. Schematic Diagram (Base Unit)---------------------- 84 2 Warning -------------------------------------------------------------- 4 13.3. Schematic Diagram (Base Unit_Operation) ------- 86 2.1. Battery Caution--------------------------------------------- 4 13.4.

  • Page 4: Safety Precautions

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 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 pre- vent fires, injury or electric shock, which can be caused by improper repair work. 1.

  • Page 5: Discarding Of P.c. Board

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 2.2.1. 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 manufacturer’s specific instructions for the melting points of their products and any precautions for using their product with other materials.

  • Page 6: Specifications

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 3 Specifications Note: • Design and specifications are subject to change without notice. Note for Service: • Operation range: Up to 300 m outdoors, Up to 50 m indoors, depending on the condition. • Analog telephone connection: Telephone Line •...

  • Page 7: Technical Descriptions

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4 Technical Descriptions 4.1. Block Diagram (Base Unit)

  • Page 8: Circuit Operation (Base Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.2. Circuit Operation (Base Unit) 4.2.1. Outline Base Unit consists of the following ICs as shown in Block Diagram (Base Unit) (P.7). • 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)

  • Page 9: Power Supply Circuit

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.2.2. Power Supply Circuit The power is supplied to the DECT BBIC, RF Module, EEPROM and Charge Contact from AC Adaptor (+6.5 V) as shown in Fig.101. The power supply is as follows; • DECT BBIC (IC7): DC Jack (+6.5 V) →D1→ IC1 → IC7 DC Jack (+6.5 V) →D1→...
  • Page 10 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.2.3. Telephone Line Interface <Function> • Bell signal detection • Clip signal detection • ON/OFF hook circuit Bell & Clip (: Calling Line Identification Presentation: Caller ID) signal detection: In the standby mode, Q3 is open to cut the DC loop current and decrease the ring load. When ring voltage appears at the L1T (A) and L1R (B) leads (when the telephone rings), the AC ring voltage is transferred as follows;...

  • Page 11: Block Diagram (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.3. Block Diagram (Handset)

  • Page 12: Circuit Operation (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.4. Circuit Operation (Handset) 4.4.1. Outline Handset consists of the following ICs as shown in Block Diagram (Handset) (P.11). • DECT BBIC (Base Band IC): IC1 - All data signals (forming/analyzing ACK or CMD signal) - All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter, EEPROM, LCD, RF Power Amp.) - PLL Oscillator - Detector - Compress/Expander...

  • Page 13: Circuit Operation (Charger Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.5. Circuit Operation (Charger Unit) 4.5.1. Power Supply Circuit The power supply is as shown.

  • Page 14: Signal Route

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 4.6. Signal Route...
  • Page 15 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E...

  • Page 16: Location Of Controls And Components

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 5 Location of Controls and 5.1.2. Handset Components 5.1. Controls 5.1.1. Base Unit...

  • Page 17: Setting

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 6 Installation Instructions 6.2. Battery 6.2.1. Battery Installation 6.1. Connections See For Service Hint (P.28) 6.2.2. Battery Charge...
  • Page 18 In that case, by recharging the battery as mentioned above, you will get a correct indication of the battery strength. 6.2.3. Battery Level 6.2.4. Panasonic Ni-MH Battery Performance (supplied batteries)

  • Page 19: Operating Instructions

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 7 Operating Instructions 7.1. Programmable Settings You can customise the unit by programming the following features using the handset. 7.1.1. Programming by scrolling through the display menus...

  • Page 20: Answering System Setting

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E *1 The item will not be reset when pressing keys. Refer to How to Clear User Setting (P.35). *2 The item will not be reset when pressing keys. Refer to How to Clear User Setting (P.35). Cross Reference: Registering a Handset to a Base Unit (P.22) 7.1.2.
  • Page 21 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 7.1.3. SMS Setting Note: (*1) If the password of a private mailbox is forgotten, refer to For Service Hint (P.28)

  • Page 22: Registering A Handset To A Base Unit

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 7.2. Registering a Handset to a Base Unit If you forget your PIN, see "Programmable settings" in Troubleshooting (P.24) Note: • When you purchase an additional handset, refer to the additional handset's installation manual for registration. 7.2.1. Deregistering a Handset 7.2.2.

  • Page 23: Copying Phonebook Entries

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 7.3. Copying Phonebook Entries You can copy phonebook entries to the phonebook of another compatible Panasonic handset. Note: • Category settings for phonebook entries are not copied. Copying all entries 7.3.1. 7.4. Error Messages...

  • Page 24: Troubleshooting

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 7.5. Troubleshooting...
  • Page 25 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E...
  • Page 26 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E...
  • Page 27 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E...

  • Page 28: For Service Hint

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 7.6. For Service Hint Cross Reference: Battery Charge (P.17) Frequently Used Items (Base Unit) (P.30)

  • Page 29: Service Mode

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 8 Service Mode 8.1. Engineering Mode 8.1.1. Base Unit...
  • Page 30 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Frequently Used Items (Base Unit) ex.) Items Address Default Data New Data Remarks C-ID (FSK) sensitivity 04 B6 01 (6 dB up) 02 (12 dB up) When hex changes from “00” to “01” or “02”, gain increases by 6 dB or 12 dB. C-ID (DTMF) sensitivity 04 C4 60 (6 dB up)
  • Page 31 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 8.1.2. Handset...
  • Page 32 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Frequently Used Items (Handset) ex.) Items Address Default Data New Data Possible Adjusted Possible Adjusted Remarks Value MAX (hex) Value MIN (hex) Sending level 00 06 Adjusted value Given value (*2) Receiving level 00 07 Adjusted value Given value (*3) Battery Low 00 04...

  • Page 33: Copying Phonebook Items When Repairing

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 8.2. Copying Phonebook Items when Repairing You can copy the handset phonebook to another (compatible Panasonic) handset. This will help to save the original phonebook data which the customer has registered. Available models: KX-TG8421/KX-TG8422/KX-TG8423/KX-TG8424 Refer to the following procedures.
  • Page 34 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Note: • BS=Base Unit , HS=Handset • If the max number of handsets are already registered to the base unit, a new handset cannot be registered. • To register the handset, refer to Registering a Handset to a Base Unit (P.22) •...

  • Page 35: How To Clear User Setting

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 8.3. How to Clear User Setting Units are reset to the Factory settings by this operation (Erase recorded Voice messages*, stored Phone numbers, Caller list and etc.) Note: • Some menus are not reset. Refer to Operating Instructions (P.19). •...

  • Page 36: Troubleshooting Guide

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9 Troubleshooting Guide 9.1. Troubleshooting Flowchart Flow Chart Cross Reference: Check Power (P.37) Bell Reception (P.47) Check Battery Charge (P.38) Check Link (P.39) Check the RF part (P.43) Check Handset Transmission (P.46) Check Handset Reception (P.46) Signal Route (P.14) Check Caller ID (P.46) Check TAM Operation (P.47)

  • Page 37: Check Power

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.1. Check Power 9.1.1.1. Base Unit Is the AC Adaptor inserted into AC outlet? (*1) Cross Reference: Note: Power Supply Circuit (P.9) (*1) Refer to Specifications (P.6) for part number and supply voltage of AC Adaptor. 9.1.1.2. Handset Cross Reference: Power Supply Circuit/Reset Circuit (P.12)

  • Page 38: Base Unit

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.2. Check Battery Charge 9.1.2.1. Base Unit Cross Reference: Charge Circuit (P.12) 9.1.2.2. Handset Cross Reference: Check Power (P.37) Charge Circuit (P.12) 9.1.2.3. Charger Unit Cross Reference: Charge Circuit (P.12)

  • Page 39: Check Link

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.3. Check Link 9.1.3.1. Base Unit Note: (*1) Refer to Troubleshooting by Symptom (Base Unit and Charger Unit) (P.48) Cross Reference: Check Point (Base Unit) (P.48) Power Supply Circuit (P.9)
  • Page 40 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Cross Reference: Check Point (Base Unit) (P.48)
  • Page 41 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.3.2. Handset Cross Reference: Check Point (Handset) (P.52) Power Supply Circuit/Reset Circuit (P.12)
  • Page 42 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Cross Reference: Check Point (Handset) (P.52)

  • Page 43: Check The Rf Part

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.4. Check the RF part 9.1.4.1. Finding out the Defective part After All the Checkings or Repairing 1. Re-register the checked Handset to the checked Base Unit, and Regular HS to Regular BU. Note: If you need to register a handset, refer to Registering a Handset to a Base Unit (P.22)
  • Page 44 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.4.2. RF Check Flowchart Each item (1 ~ 3) of RF Check Flowchart corresponds to Check Table for RF part (P.45). Please refer to the each item. Note: (*1) Base unit - refer to (G) of Check Point (Base Unit) (P.48) Handset - refer to (H) of Check Point (Handset) (P.52)
  • Page 45 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.4.3. Check Table for RF part Item BU (Base Unit) Check HS (Handset) Check Link Confirmation Normal 1. Register Regular HS to BU (to be 1. Register HS (to be checked) to Regular checked). HS, BU Mode: [Normal mode] 2.

  • Page 46: Check Handset Transmission

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.5. Check Handset Transmission Cross Reference: Signal Route (P.14) 9.1.6. Check Handset Reception Cross Reference: How to Check the Handset Speaker or Receiver (P.71). Signal Route (P.14) 9.1.7. Check Caller ID Cross Reference: Signal Route (P.14)
  • Page 47 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.1.8. Bell Reception 9.1.8.1. Base Unit 9.1.8.2. Handset Cross Reference: Telephone Line Interface (P.10) Check Link (P.39) How to Check the Handset Speaker or Receiver (P.71) 9.1.9. Check TAM Operation Cross Reference: Power Supply Circuit (P.9) Note: (*1) When replacing FLASH MEMORY (IC421), TAM data need to be written to it. Refer to Base Unit of Things to Do after Replacing IC or X'tal (P.68)

  • Page 48: Troubleshooting By Symptom (Base Unit And Charger Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.2. Troubleshooting by Symptom (Base Unit and Charger Unit) If your unit has below symptoms, follow the instructions in remedy column. Remedies depend on whether you have DECT tester (*1) or not. Note: (*1) A general repair is possible even if you don’t have the DECT tester because it is for confirming the levels, such as Acoustic level in detail.
  • Page 49 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Items Check Procedure Check or Point Replace Parts 1. Connect Telephone Socket to Tel-simulator which is connected with 600 Ω. (H)* Hookswitch Check with L1, L2, Q3, R14, DC Characteristics 2. Set line voltage to 48 V and line current to 40mA at off-hook condition of nor- R15, Q4, R16, mal telephone.
  • Page 50 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Items Check Procedure Check or Point Replace Parts (M)* Frequency Drift Confir- Follow steps 1 to 6 of (J). IC7, mation ANTI_TP 7.Confirm that the frequency drift is < ± 35 kHz/ms. C802~C806, C808~C814, C820, C819, C822, C823, C825, C827, C826, C834, C851, C853, C859~C861,...
  • Page 51 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Items Check Procedure Check or Point Replace Parts Audio Check 1. Link with Handset. IC7, SA1, L1, 2. Input -45dBm/1kHz to MIC of Handset. L2, D3, Q3, Q4, Measure the Level at Line I/F and distortion level. R14, R15, R16, 3.

  • Page 52: Troubleshooting By Symptom (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.3. Troubleshooting by Symptom (Handset) If your unit has below symptoms, follow the instructions in remedy column. Remedies depend on whether you have DECT tester (*1) or not. Note: (*1) A general repair is possible even if you don’t have the DECT tester because it is for confirming the levels, such as Acoustic level in detail.
  • Page 53 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Items Check Procedure Check or Point Replace Parts (F)* Battery Monitor Check 1. Apply 2.25 V between BATT+ and BATT-. IC1, F1, C1, 2. Execute the command R12, R45 sendchar PAD sendchar LED 0 sendchar CRX 0 1 sendchar AD1 It assumes that the return value is XX.
  • Page 54 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Items Check Procedure Check or Point Replace Parts (K)* Frequency Offset Confir- Follow steps 1 to 3 of (I). IC1, mation 4.Confirm that the frequency Offset is < ± 50 kHz. C802~C806, C808~C814, C819~C820, C822, C825~C827, C834, C859~C864, L801~L804, DA801, R801~R808 (L)* Frequency Drift Confir-...
  • Page 55 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 9.3.2. Troubleshooting for Speakerphone When the customer’s telephone line corresponds to the following conditions, and the transmission signal of SP-Phone is inter- rupted, performing the next set up to a cordless handset will improve it to some extent. Conditions 1.

  • Page 56: Disassembly And Assembly Instructions

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 10 Disassembly and Assembly Instructions 10.1. Disassembly Instructions 10.1.1. Base Unit...
  • Page 57 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E...
  • Page 58 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 10.1.2. Handset...
  • Page 59 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 10.1.3. Charger Unit...

  • Page 60: How To Replace The Handset Lcd

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 10.2. How to Replace the Handset LCD...

  • Page 61: Measurements And Adjustments

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11 Measurements and Adjustments 11.1. The Setting Method of JIG (Base Unit) 11.1.1. Preparation 11.1.1.1. Equipment Required • DECT tester: Rohde & Schwarz, CMD 60 is recommended. • Frequency counter: It must be precise enough to measure intervals of 1 Hz (precision; ±4 ppm). Hewlett Packard, 53131A is recommended.
  • Page 62 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.1.2.2. Batch file Setting Note: • “****” varies depending on the country. 11.1.2.3. Commands See the table below for frequently used commands. Command name Function Example rdeeprom Read the data of EEPROM Type “rdeeprom 00 00 FF”, and the data from address “00 00”...

  • Page 63: Adjustment Standard (Base Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.2. Adjustment Standard (Base Unit) When connecting the simulator equipments for checking, please refer to below. 11.2.1. Bottom View Note: (A) - (T) is referred to Check Point (Base Unit) (P.48)

  • Page 64: Adjustment Standard (Charger Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.3. Adjustment Standard (Charger Unit) When connecting the simulator equipment for checking, please refer to below. 11.3.1. Bottom View Digital Volt Meter /2 W DC POWER DC 6.5 V Note: (A) is referred to Check Point (Charger Unit) (P.51)

  • Page 65: The Setting Method Of Jig (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.4. The Setting Method of JIG (Handset) 11.4.1. Preparation 11.4.1.1. Equipment Required • DECT tester: Rohde & Schwarz, CMD 60 is recommended. • Frequency counter: It must be precise enough to measure intervals of 1 Hz (precision; ±4 ppm). Hewlett Packard, 53131A is recommended.
  • Page 66 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.4.2.2. Batch file Setting Note: • “*****” varies depending on the country. 11.4.2.3. Commands See the table below for frequently used commands. Command name Function Example rdeeprom Read the data of EEPROM Type “rdeeprom 00 00 FF”, and the data from address “00 00”...

  • Page 67: Adjustment Standard (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.5. Adjustment Standard (Handset) When connecting the simulator equipments for checking, please refer to below. 11.5.1. Component View Note: (A) - (R) is referred to Check Point (Handset) (P.52)

  • Page 68: Things To Do After Replacing Ic Or X'tal

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.6. Things to Do after Replacing IC or X'tal Cautions: Some of the content on this page may not apply to models from some countries. 11.6.1. Base Unit Before making the following adjustment, ensure you have carried out PC Setting (P.61) in The Setting Method of JIG (Base Unit).
  • Page 69 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.6.2. Handset Before making the following adjustment, ensure you have carried out PC Setting (P.65) in The Setting Method of JIG (Hand- set). Items Necessary Adjustment BBIC (FLASH type) Programs for Voice processing, interface for RF 1. Make sure to connect the JIG cable, then detach the DC (IC1) and EEPROM Power.

  • Page 70: Rf Specification

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.7. RF Specification 11.7.1. Base Unit Item Value Refer to -. * TX Power 19 dBm ~ 25 dBm Check Point (Base Unit) (J) Modulation -370±30/+370±30 kHz/div & Modulated Check Point (Base Unit) (K) width 690 kHz Frequency Offset -50 kHz ~ +50 kHz Check Point (Base Unit) (L) Frequency Drift...

  • Page 71: How To Check The Handset Speaker Or Receiver

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 11.8. How to Check the Handset Speaker or Receiver 1. Prepare the digital voltmeter, and set the selector knob to ohm meter. 2. Put the probes at the speaker terminals as shown below. 11.9. Frequency Table (MHz) BASE UNIT HANDSET Channel No Transmit Frequency...

  • Page 72: Miscellaneous

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 12 Miscellaneous 12.1. CPU Data (Base Unit) 12.1.1. IC7 (BBIC) Pin No. Description Connection at Normal mode at Reset mode VSS_LNA1 RF_RXp RF_RXp RF_RXn RF_RXn VSS_LNA2 RFP1 RXON O_0/1 Hi-Z RFP0 ANT1 O_0/1 Hi-Z REF_RES REF_RES AVS_XTAL XTAL2 XTAL2 XTAL1 XTAL1 AVD_XTAL...
  • Page 73 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Pin No. Description Connection at Normal mode at Reset mode P0_1/URX I_0/1 P0_0/UTX O_0/1 RSTn RSTn O_0/1 JTAG D.I/O JTAG I/O_0/1 I-PU P2_5/PCM_FSC/SF EEP_WP P2_4/SCL1/PCM_DO/ TEST P2_3/SDA1/PCM_DI/DP2 N.C. P2_2/PCM_CLK/CLK100 N.C. P2_1/ECZ2/PWM1/LED4 LED2 P2_0/ECZ1/PWM0/LED3 LED1 VDD2 +1.8V LDORF_CTRL LDORF_CTRL RF_SUPPLY2 RF_SUPPLY2 RF0n ANT2...

  • Page 74: Cpu Data (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 12.2. CPU Data (Handset) 12.2.1. IC1 (BBIC) Pin No. Description Connection at Normal mode at Reset mode VSS_LNA1 RF_RXp RF_RXp RF_RXn RF_RXn VSS_LNA2 RFP1 RXON O_0/1 RFP0 ANT1 O_0/1 REF_RES REF_RES AVS_XTAL XTAL2 XTAL2 XTAL1 XTAL1 AVD_XTAL AVD_XTAL RF_SUPPLY1 RF_SUPPLY1 LDO_CTRL LDO_CTRL...
  • Page 75 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Pin No. Description Connection at Normal mode at Reset mode JTAG D.I/O JTAG D.I/O I-PU P2_5/PCM_FSC/SF LCD_CSB I-PU P2_4/SCL1/PCM_DO/ N.C. P2_3/SDA1/PCM_DI/DP2 N.C. P2_2/PCM_CLK/CLK100 LCD_RESET P2_1/ECZ2/PWM1/LED4 N.C. P2_0/ECZ1/PWM0/LED3 BELL_LED_A VDD2 +1.8V LDORF_CTRL N.C. RF_SUPPLY2 RF_SUPPLY2 RF0n ANT2 RFP4 RFP3 PSEL VDD_PADR VDD_PADRV VSS_PADR1...

  • Page 76: How To Replace The Flat Package Ic

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 12.3. How to Replace the Flat Package IC Even if you do not have the special tools (for example, a spot heater) to remove the Flat IC, with some solder (large amount), a soldering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins. 12.3.1.
  • Page 77 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 12.3.3. How to Install the IC 1. Temporarily fix the FLAT PACKAGE IC, soldering the two marked pins. *Check the accuracy of the IC setting with the corresponding soldering foil. 2. Apply flux to all pins of the FLAT PACKAGE IC. 3.

  • Page 78: How To Replace The Llp (Leadless Leadframe Package) Ic

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 12.4. How to Replace the LLP (Leadless Leadframe Package) IC 12.4.1. Preparation • PbF (: Pb free) Solder • Soldering Iron Tip Temperature of 700°F ± 20°F (370°C ± 10°C) Note: We recommend a 30 to 40 Watt soldering iron. An expert may be able to use a 60 to 80 Watt iron where someone with less experience could overheat and damage the PCB foil.
  • Page 79 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 1. Put the shield case. 2. Solder the surroundings.

  • Page 80: Terminal Guide Of The Ics, Transistors And Diodes

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 12.5. Terminal Guide of the ICs, Transistors and Diodes 12.5.1. Base Unit 12.5.2. Handset 12.5.3. Charger Unit...
  • Page 81 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Memo...

  • Page 82: Schematic Diagram

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 13 Schematic Diagram 13.1. For Schematic Diagram 13.1.1. Base Unit (Schematic Diagram (Base Unit)) Notes: 1. DC voltage measurements are taken with voltmeter from the negative voltage line. 2. The schematic diagrams may be modified at any time with the development of new technology. 13.1.2.
  • Page 83 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Memo:...

  • Page 84: Schematic Diagram (Base Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 13.2. Schematic Diagram (Base Unit) ANT1_TP ANT2_TP ANT_1 ANT_2 C851 C853 W 0.15mm W 0.15mm L 22+/-4mm L 22+/-4mm Beep 1st or 4th layer 1st or 4th layer Bell signal DA802 *R86 W 0.15mm L 22+/-4mm 1st or 4th layer W 0.15mm *R87 L 20+/-2mm...
  • Page 85 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Loop Current LINE_DC *R30 100k (1005) NC C155 *R13 TP10 *R20 1.8k R116 2.2k 100k +1.8V 5.6M +1.8V 100k GND GND HAK_CL1 5.6M Caller ID RX_AF Bell signal 180k 4.7M 680p *C147 TX _AF 180k 4.7M *C148 Bell signal 680p 1.8V 3.0V...

  • Page 86: Schematic Diagram (Base Unit_Operation)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 13.3. Schematic Diagram (Base Unit_Operation) 2APVCC LED902 MEG_LED LED901 ANS_LED KEYS_B KEYIN1 KEYIN2 KEYIN3 KEYS_C KEYS_D KEYS_E ANS1 ERASE MSG2 SKIP MSG1 DOWN LOCAT/INT STOP KX-TG8421/8422/8423/8424 SCHEMATIC DIAGRAM (Base Unit_Operation)
  • Page 87 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Memo...

  • Page 88: Schematic Diagram (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 13.4. Schematic Diagram (Handset) Charge Current BATTERY BATT+ 5.6n C1 CP1 BATTERY 6.3V 330u To Battery C150 R330 BATT- C331 R331 C2 CP2 6.3V C332 330u R332 X_CLK 2.5V 4.0V CP+2.5V CP+4.0V CP2.5V CP4.0V 1.2k 3.9k K10u CHG(+) K0.1u K10u To Charge C147...
  • Page 89 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E W 0.15mm L 20+/-2mm 1.8V 3rd layer (MAX500mA) R807 RXON +1.8V 1.8V L801 C827 C826 RX_RF K2.2u ANT_TP RF_RXn C859 C803 1.5p DA801 RF_RXp W 0.125mm L 7.6mm Gap 0.125mm W 0.15mm W 0.15mm 1st layer L 5.0mm L 5.0mm CP+2.5V 1st layer 1st layer...

  • Page 90: Schematic Diagram (Charger Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 13.5. Schematic Diagram (Charger Unit) R1 10 SCHEMATIC DIAGRAM (Charger Unit)

  • Page 91: Printed Circuit Board

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 14 Printed Circuit Board 14.1. Circuit Board (Base Unit_MAIN) 14.1.1. Component View R129 R130 C157 R126 C516 C506 R657 C515 C514 C513 C512 C861 R511 R808 R542 C511 C163 R532 R801 C517 R802 C860 C518 C520 C823 R805 IC801 C519 R803 R804...
  • Page 92 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 14.1.2. Bottom View VDD4 (CP3.0V) (10.368MHZ) CHG- VDD1 1.8V CHG+ KX-TG8421/8422/8423/8424 CIRCUIT BOARD (Base Unit_Main (Bottom View))

  • Page 93: Circuit Board (Base Unit_Operation)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 14.2. Circuit Board (Base Unit_Operation) 14.2.1. Component View PNLB1092Z KX-TG7431/8421/8431H LED901 ERASE ANS1 LED902 MSG1 MSG2 SKIP STOP LOCAT/INT DOWN KEYS_E KEYS_C KEYIN2 KEYS_B MEG_LED KEYS_D KEYIN3 KEYIN1 ANS_LED 2APVCC KX-TG8421/8422/8423/8424 CIRCUIT BOARD (Base Unit_Operation (Component View))

  • Page 94: Circuit Board (Handset)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 14.3. Circuit Board (Handset) 14.3.1. Component View PNLB1104Z KX-TGA840XX EU RECEIVER RCV+ RCV- C152 C138 C139 L804 SPEAKER C863 C864 C814 C811 C804 IC801 C813 D14 D13 R802 L802 C802 R209 R208 JTAG R805 TEST C834 R225 C837 R807 R203 1.8V POWER...
  • Page 95 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 14.3.2. Bottom View LED12 PNLB1104Z KX-TGA840XX EU C105 SOFT_C SOFT_A TALK LED4 LED1 LED5 LED2 LED6 LED3 CARBON_CL1 MIC- MIC+ KX-TGA840 CIRCUIT BOARD (Handset_Main (Bottom View))

  • Page 96: Circuit Board (Charger Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 14.4. Circuit Board (Charger Unit) 14.4.1. Component View CIRCUIT BOARD (Charger unit (Component View)) 14.4.2. Bottom View TP4 (GND) CIRCUIT BOARD (Charger unit (Bottom View))

  • Page 97: Exploded View And Replacement Parts List

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15 Exploded View and Replacement Parts List 15.1. Cabinet and Electrical Parts (Base Unit) Note: (*1) Attach the double side tape to the exact location described above. (*2) Refer to the spacer (No.109) of Cabinet and Electrical Parts (Handset) (P.98)

  • Page 98: Cabinet And Electrical Parts (Handset)

    (*1) This cable is fixed by welding. Refer to How to Replace the Handset LCD (P.60). (*2) The rechargeable Ni-MH battery P03Por HHR-4MRE is available through sales route of Panasonic. (*3) Attach the spacer (No. 123) to the exact location described above.

  • Page 99: Cabinet And Electrical Parts (Charger Unit)

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.3. Cabinet and Electrical Parts (Charger Unit)

  • Page 100: Accessories And Packing Materials

    KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.4. Accessories and Packing Materials 15.4.1. KX-TG8421EB/EM/EN...
  • Page 101 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.4.2. KX-TG8422EB/EM/EN...
  • Page 102 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.4.3. KX-TG8423EB/EM/EN...
  • Page 103 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.4.4. KX-TG8424EB/EM/EN...
  • Page 104 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.4.5. KX-TGA840EB/EM/EN...

  • Page 105: Replacement Part List

    PANEL,LCD (for ABS-HB IC801 C1CB00001842 IC (*3) TG8421EM) (TRANSISTORS) PNGP1050X3 PANEL,LCD (for ABS-HB B1ACGP000007 TRANSISTOR(SI) TG8421EN) PQVTBF822T7 TRANSISTOR(SI) PNGG1035Z1 GRILLE (for KX-TG8421EB) ABS-HB 2SD0874AS TRANSISTOR(SI) PNGG1035Z2 GRILLE (for KX-TG8421EM/ ABS-HB B1ADGE000004 TRANSISTOR(SI) B1ADGE000004 TRANSISTOR(SI) PNKM1071Y1 CABINET BODY (for ABS-HB TG8421EB)
  • Page 106 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Safety Ref. Part No. Part Name & Description Remarks Safety Ref. Part No. Part Name & Description Remarks B0EDER000009 DIODE(SI) R426 ERJ2GEJ561 MA111 DIODE(SI) R427 ERJ2GEJ561 MA111 DIODE(SI) R428 ERJ2GEJ561 MA111 DIODE(SI) R429 ERJ2GEJ332 3.3k PQVDRLZ20A DIODE(SI) R430 ERJ2GEJ100 B0ECKM000008 DIODE(SI) R511 ERJ2GE0R00...
  • Page 107 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E Safety Ref. Part No. Part Name & Description Remarks Safety Ref. Part No. Part Name & Description Remarks C305 ECUE0J105KBQ 1 PNGP1047Z3 PANEL,LCD (for PMMA-HB TGA840EM) C421 ECUE1C103KBQ 0.01 PNGP1047Z2 PANEL,LCD (for PMMA-HB C422 ECUE1A104KBQ 0.1 TGA840EN) C511 ECUE1H100DCQ 10p PNGG1032Z1 GRILL,FRAME (for...
  • Page 108 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E (*4) When replacing the handset LCD, See How to Safety Ref. Part No. Part Name & Description Remarks Replace the Handset LCD(P.60). ERJ2GEJ471 (*5) Backside of this IC has a ground plate. ERJ2GEJ221 (*6) Supplied IC is Flat Package Type. ERJ2GEJ332 3.3k ERJ2GEJ103...
  • Page 109 F1G1HR70A480 0.7p (*1) You can download and refer to the Operating Instruc- C822 ECUE1H100DCQ 10p C825 ECUE1H100DCQ 10p tions (Instruction book) on TSN Server. C826 F1G1H2R0A480 2.0p 15.5.4.1. KX-TG8421EB/EM/EN C827 ECUE1H100DCQ 10p C834 F1G1HR50A480 0.5p C859 F1G1H4R0A480 4p C860 ECUE1H100DCQ 10p Safety Ref.
  • Page 110 KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E 15.5.4.3. KX-TG8423EB/EM/EN Part No. Part Name & Description Remarks Safety Ref. Safety Ref. Part No. Part Name & Description Remarks PQZZ1CD300E JIG CABLE (*1) PNZZTG8421E BATCH FILE CD-ROM (*1) A201 PQLV219EY AC ADAPTOR A202 PQJA87S CORD, TELEPHONE A203 PNQX1708Z INSTRUCTION BOOK (*1) A204 PNQW1548Z...

This manual is also suitable for:

Kx-tg8421emKx-tg8421enKx-tg8422ebKx-tg8422emKx-tg8422enKx-tg8423eb ... Show all

Table of Contents