Panasonic KX-TG7841S Service Manual

Panasonic KX-TG7841S Service Manual

Handset/base unit
Table of Contents

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KX-TGA680
(Handset)
(Charger Unit)
Configuration for each model
Model No
Base Unit
Handset
KX-TG7841 1 (TG7841) 1 (TGA680)
KX-TG7842 1 (TG7841) 2 (TGA680)
KX-TG7843 1 (TG7841) 3 (TGA680)
KX-TG7844 1 (TG7841) 4 (TGA680)
KX-TG7845 1 (TG7841) 5 (TGA680)
KX-TG365
1 (TG7841) 5 (TGA680)
KX-TG7871 1 (TG7871) 1 (TGA680)
KX-TG7872 1 (TG7871) 2 (TGA680)
KX-TG7873 1 (TG7871) 3 (TGA680)
KX-TG7874 1 (TG7871) 4 (TGA680)
KX-TG7875 1 (TG7871) 5 (TGA680)
KX-TG385
1 (TG7871) 5 (TGA680)
KX-TGA680*
1 (TGA680)
*KX-TGA680 is also an optional accessory, which contains a
handset and a charger.
KX-TG7841/7871
(Base Unit)
Charger Unit Expandable
Up to 6
1
Up to 6
2
Up to 6
3
Up to 6
4
Up to 6
4
Up to 6
Up to 6
1
Up to 6
2
Up to 6
3
Up to 6
4
Up to 6
4
Up to 6
1
Telephone Equipment
KX-TG7841S
Model No.
KX-TG7842S
KX-TG7843S
KX-TG7844S
KX-TG7845S
KX-TG365SK
KX-TG7871S
KX-TG7872S
KX-TG7873S
KX-TG7874S
KX-TG7875S
KX-TG385SK
KX-TGA680S
KX-TGA20B
Link-to-Cell Cellular Convergence
Solution
Black
B:
Version
S: Silver Version
(for U.S.A.)
© Panasonic System Networks Co., Ltd. 2013
Unauthorized copying and distribution is a violation
of law.
ORDER NO. KM41302655CE
F13

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Summary of Contents for Panasonic KX-TG7841S

  • Page 1 KX-TG385 1 (TG7871) 5 (TGA680) Up to 6 KX-TGA680* 1 (TGA680) *KX-TGA680 is also an optional accessory, which contains a handset and a charger. © Panasonic System Networks Co., Ltd. 2013 Unauthorized copying and distribution is a violation of law.
  • Page 2 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 WARNING This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products powered by electricity should be serviced or repaired only by experienced professional technicians.
  • Page 3: Table Of Contents

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 TABLE OF CONTENTS PAGE PAGE 1 Safety Precautions----------------------------------------------- 5 10.1.7. Registering a Handset to the Base Unit ------- 46 1.1. For Service Technicians --------------------------------- 5 10.1.8. Deregistering a Handset--------------------------- 46 2 Warning -------------------------------------------------------------- 5 10.1.9. Check Handset Transmission -------------------- 47 2.1.
  • Page 4 16.2. Cabinet and Electrical Parts (Handset) ------------- 90 16.3. Cabinet and Electrical Parts (Charger Unit) ------- 91 16.4. Accessories and Packing Materials ----------------- 92 16.4.1. KX-TG7841S ----------------------------------------- 92 16.4.2. KX-TG7842S ----------------------------------------- 93 16.4.3. KX-TG7843S ----------------------------------------- 94 16.4.4. KX-TG7844S ----------------------------------------- 95 16.4.5.
  • Page 5: Safety Precautions

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 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.
  • Page 6: Suggested Pbf Solder

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 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 7: Specifications

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 3 Specifications ■ Standard: ■ Bit rate: DECT 6.0 (Digital Enhanced Cordless 1.152Mbit/s (DECT 6.0) Telecommunications 6.0) 1.0 Mbit/s (Bluetooth) Bluetooth wireless technology 2.1 ■ Modulation: ■ Number of channels: GFSK (Gaussian Frequency Shift Keying) 60 Duplex Channels (DECT 6.0) ■...
  • Page 8: Technical Descriptions

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4 Technical Descriptions 4.1. Circuit Configuration of TG78xx Series Phones TG78xx consists of DECT cordless telephone and Bluetooth Module. Both voices of transmission and reception are transferred by PCM. BBIC on DECT side controls the cordless telephone system, which makes control data communication with BT_IC on BT Module in serial data.
  • Page 9: Us-Dect Description

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.2. US-DECT Description The frequency range of 1.92 GHz-1.93 GHz is used. Transmitting and receiving carrier between base unit and handset is same frequency. Refer to Frequency Table (P.66). 4.2.1. TDD Frame Format 5 ms 5 ms Up Link ( Handset - > Base Unit ) Down Link ( Base Unit - >...
  • Page 10: Signal Flowchart In The Radio Parts

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.2.3. Signal Flowchart in the Radio Parts Reception Base unit: A voice signal from TEL line is encoded to digital data and converted into a 1.9GHz modulated radio signal by BBIC(IC501). The RF signal, after which is amplified in BBIC, is fed to selected antenna. Handset: As for a handset RF, RF signal is received in one antenna.
  • Page 11: Block Diagram (Base Unit_Main)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.3. Block Diagram (Base Unit_Main)
  • Page 12: Tel Interface Circuit

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.4. Tel Interface Circuit...
  • Page 13: Block Diagram (Base Unit_Rf Part)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.5. Block Diagram (Base Unit_RF Part)
  • Page 14: Circuit Operation (Base Unit)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.6. Circuit Operation (Base Unit) General Description: (BBIC, Flash Memory, EERROM) is a digital speech/signal processing system that implements all the functions of speech compression, record and playback, and memory management required in a digital telephone answering machine. The BBIC system is fully controlled by a host processor. The host processor provides activation and control of all that functions as follows.
  • Page 15: Power Supply Circuit/Reset Circuit

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.6.6. Power Supply Circuit/Reset Circuit The power supply voltage from AC adaptor is converted to VBAT (3.0V) in IC302. And +3.0V for peripherals and analog part is insulated from VBAT by Doubler of BBIC. Circuit Operation: VDD4 +5.5V +3.0V VDD3 IC502 IC501...
  • Page 16 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.6.6.1. Charge Circuit The voltage from the AC adaptor is supplied to the charge circuits. +5.5V F301 R373 CHARGE+ C351 CHARGE-...
  • Page 17: Telephone Line Interface

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.6.7. Telephone Line Interface Telephone Line Interface Circuit: Function • Bell signal detection • ON/OFF hook and pulse dial circuit • Side tone circuit Bell (RINGING) signal detection and OFF HOOK circuit: In the idle mode, Q141 is open to cut the DC loop current and decrease the ring load. When ring voltage appears at the Tip (T) and Ring (R) leads (When the telephone rings), the AC ring voltage is transferred as follows: L1T →...
  • Page 18: Parallel Connection Detect Circuit/Auto Disconnect Circuit

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.6.8. Parallel Connection Detect Circuit/Auto Disconnect Circuit Function: In order to disable call waiting and stutter tone functions when using telephones connected in parallel, it is necessary to have a circuit that judges whether a telephone connected in parallel is in use or not. This circuit determines whether the telephone connected in parallel is on hook or off hook by detecting changes in the T/R voltage.
  • Page 19: Calling Line Identification (Caller Id)/Call Waiting Caller

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.6.9. Calling Line Identification (Caller ID)/Call Waiting Caller ID Function: Caller ID The caller ID is a chargeable ID which the user of a telephone circuit obtains by entering a contract with the telephone company to utilize a caller ID service. For this reason, the operation of this circuit assumes that a caller ID service contract has been entered for the circuit being used.
  • Page 20 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Call Waiting Caller ID Calling Identity Delivery on Call Waiting (CIDCW) is a CLASS service that allows a customer, while off-hook on an existing call, to receive information about a calling party on a waited call. The transmission of the calling information takes place almost immediately after the customer is alerted to the new call so he/she can use this information to decide whether to take the new call.
  • Page 21: Block Diagram (Handset)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.7. Block Diagram (Handset) ANT1 EEPROM 13.824 MHz VBAT CHG_DET RF part CHARGE RSTN RESET CONTROL CHARGE CHG_CTL POWER SUPPLY CONTROL BATTERY_ON VBAT BATTERY BBIC Receiver HSSPOUTP Headset Jack LOUT HSMIP 4.0V VBAT CN431 CHARGE HEADSET_DET (KEY) CP_OFF PUMP KEY_LED Monitor SP SPOUTP...
  • Page 22: Block Diagram (Handset_Rf Part)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.8. Block Diagram (Handset_RF Part) KX-TGA680 BLOCK DIAGRAM (Handset_RF Part)
  • Page 23: Circuit Operation (Handset)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.9. Circuit Operation (Handset) 4.9.1. Outline Handset consists of the following ICs as shown in Block Diagram (Handset) (P.21). • DECT BBIC (Base Band IC): IC1 - All data signals (forming/analyzing ACK or CMD signal) - All interfaces (ex: Key, Detector Circuit, Charge, EEPROM, LCD) •...
  • Page 24: Charge Circuit

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.9.3. Charge Circuit Circuit Operation: When charging the handset on the Base Unit, the charge current is as follows; DCP(5.5V) → F301 → R371 → R372 → D362 → CHARGE+(Base) → CHARGE+(Handset) → R8 → Q3 → F1 → BATTERY+... Battery...
  • Page 25: Behavior Of Electric Power Failure

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.10. Behavior of Electric Power Failure In case that the power from AC adaptor is lost and lose radio waves, BBIC (IC1) turns Q11 ON since handset presumes that base unit's power is falied. Base unit detects that power voltage of AC adaptor +5.5V is OFF, then turns Q351 ON. It's possible to use the units during the power failure, supplying power to VBAT of base unit from battery of handset through Q10, CHG terminal and Q351.
  • Page 26: Signal Route

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 4.12. Signal Route SIGNAL ROUTE ROUTE HANDSET TX HANDSET MIC - C11/13 - RA4 - IC1(22/23) - <HANDSET_RF_TX_ROUTE> - ANT. --- ANT. - <BASE_UNIT_RF_RX_ROUTE> - IC501(2/3 - 27) - C184 - Q161 -Q141 - D101 - P101 - T/R (TEL LINE) HANDSET RX T/R (TEL LINE) - P101 - D101 - Q141 - R165 - C173 - R178 - IC501(25 - 94/95) - <BASE_UNIT_RF_TX_ROUTE>...
  • Page 27 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 SIGNAL ROUTE ROUTE HANDSET MIC - C11/13 - RA4 - IC1(22/23) INTERCOM - <HANDSET_RF_TX_ROUTE> - ANT. --- HANDSET TO BASE UNIT ANT - <BASE_UNIT_RF_RX_ROUTE> - IC501(2/3 - 41/43) - SPEAKER INTERCOM MIC - C457/C458 - RA452 - IC501(37/38 - 94/95) - <BASE_UNIT_RF_TX_ROUTE> - ANT BASE UNIT --- ANT.
  • Page 28: Location Of Controls And Components

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 5 Location of Controls and Components Refer to the Operating Instructions. Note: You can download and refer to the Operating Instructions (Instruction book) on TSN Server. 6 Installation Instructions Refer to the Operating Instructions. Note: You can download and refer to the Operating Instructions (Instruction book) on TSN Server. 7 Operating Instructions Refer to the Operating Instructions.
  • Page 29: Test Mode

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 8 Test Mode 8.1. Engineering Mode 8.1.1. Base Unit Important: Make sure the address on LCD is correct when entering new data. Otherwise, you may ruin the unit. Soft keys {OFF} Navigator key/ (Volume) key Dial keypad {FLASH} {CALL WAIT} H/S LCD H/S key operation Phonebook...
  • Page 30 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Set Addr.: 7). Press , a long confirmation beep New Data will be heard. CLEAR 8). Press {OFF} to return to standby mode. Set Addr.: After that, turn the base unit power off and then power on. _ _ _ _ Note: * To enter "Set dial mode", press { } or {>} at "...
  • Page 31: Handset

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 8.1.2. Handset Important: Make sure the address on LCD is correct when entering new data. Otherwise, you may ruin the unit. Soft keys {OFF} Navigator key/ (Volume) key Dial keypad {FLASH} {CALL WAIT} H/S key operation H/S LCD 1). Press MENU Phonebook SELECT...
  • Page 32 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Frequently Used Items (Handset) ex.) Items Address Default Data New Data Possible Adjusted Possible Adjusted Remarks Value MAX (hex) Value MIN (hex) Battery Low 00 12/00 13 00 / 00 (*2) Frequency 00 07 / 00 08 00 / 01 00 02 ~ 00 06 Given value Note:...
  • Page 33: Service Mode

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 9 Service Mode 9.1. How to Clear User Setting (Handset Only) Handset Press simultaneously until a beep sound is heard. Then single handset is initialized. (The contents of user setting are reset to factory default) *Usage time is not cleared.
  • Page 34: Troubleshooting Guide

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10 Troubleshooting Guide 10.1. Troubleshooting Flowchart FLOW CHART Not working Power ON Base Unit Check Power Not recording (*1) Record Check Record No playback Playback Pre-Message Check Playback Link No link Not charged Battery Charge Check Battery Charge Check Link Range Check the RF part No voice...
  • Page 35: Check Power

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.1. Check Power 10.1.1.1. Base Unit Is the AC Adaptor inserted into AC outlet? (*1) AC Adaptor. Is output voltage of AC adaptor 5.5 V? Check Check Power Supply Circuit. Check VDD1(1.8V) :Test point (VDD1) RSTN: Reset = "High"? Check Reset Circuit.
  • Page 36: Check Record

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.2. Check Record 10.1.2.1. Base Unit Not record Incoming Message Check Telephone Line Interface Check Bell signal. [Bell]. Check Telephone Line Interface Does the unit catch line? [OFF HOOK]. Check Line In: Pin 25 of BBIC. Check ICM Recording in Signal Route. Check Auto Disconnect Circuit.
  • Page 37 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 <How to change the Auto Disconnect activation time and VOX level> A) Auto Disconnect activation time: Some Telephone Company lines (fiber or cable) ON Hook and OFF Hook voltages are lower than conventional lines, which may cause a malfunction of Auto Disconnect detection. To solve this problem, try changing the Auto Disconnect activation through the procedures below.
  • Page 38 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 B) Vox level: It makes easier to detect a small voice (caller) by raising the sensitivity of VOX level. Therefore, the recording of TAM is not turned off during detection. 1) ~ 2) are same as (A). 3) Press "5","1","1". Service ready :5 1 1 CLEAR...
  • Page 39: Check Playback

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.3. Check Playback 10.1.3.1. Base Unit Check VDD1(1.8V) :Test point (VDD1) Check Power Supply Circuit. Check output of BBIC (Pin 41,43). Check BBIC and Flash Memory. Check Speaker and its surroundings. Cross Reference: Note: Power Supply Circuit/Reset Circuit (P.15) Flash Memory is IC601.
  • Page 40: Check Link

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.5. Check Link 10.1.5.1. Base Unit Does Base Unit connect to the properly working Base Unit is OK. Check Handset. Handset? Is the voltage of VDD3 about 3.0V? Check around Power Supply Circuit. Is the voltage of VDD1 about 1.8V? Check around X501 and RF module and adjust Does the RF clock (CLK) oscillate at 10.368 MHz in Base Unit Test Mode?
  • Page 41 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.5.2. Handset Does Handset link with Base Unit? Handset is OK. Check Base Unit. (Properly working unit) Is the voltage of TP VBAT about 2.2~2.8 V? Check the batteries. Check around Power Supply Circuit/Reset Circuit. Is the voltage of TP VDDC about 1.2 V? Is the voltage of TP 3.0 V about 3.0 V? Does the RF clock (CLK) oscillate: 13.824 MHz Check around X1 and RF module and adjust...
  • Page 42: Check The Rf Part

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.6. Check the RF part 10.1.6.1. Finding out the Defective part 1. Prepare Regular HS(*1) and Regular BU(*2). 2. a. Re-register regular HS (Normal mode) to base unit (to be checked). If this operation fails in some ways, the base unit is defective. b.
  • Page 43 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.6.2. RF Check Flowchart Each item (1 ~ 5) of RF Check Flowchart corresponds to Check Table for RF part (P.44). Please refer to the each item. Start Link Control Check BBIC interface parts. confirmation signal (RF Block <->BBIC on BU/HS P.C.B) Normal confirmation X'tal...
  • Page 44 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.6.3. 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 45 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.6.4. TEST RANGE Check Circuit block which range is defective can be found by the following check. Item BU (Base Unit) Check HS (Handset) Check Range Confirmation TX TEST 1. Register Regular HS to BU (to be checked). 1. Register HS (to be checked) to Regular BU. (TX Power check) 2.
  • Page 46: Registering A Handset To The Base Unit

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.7. Registering a Handset to the Base Unit The supplied handset and base unit are pre-registered. If for some reason the handset is not registered to the base unit, re-register the handset. 1 Handset: {MENU} i # 1 3 0 2 Base unit: Press and hold {LOCATOR} for about 5 seconds until the registration tone sounds.
  • Page 47: Check Handset Transmission

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.9. Check Handset Transmission Check MIC of handset. Check handset Tx in Signal Route. Cross Reference: Signal Route (P.26) 10.1.10. Check Handset Reception Check speaker of handset. Check handset Rx in Signal Route. Cross Reference: Signal Route (P.26) Note: When checking the RF part, Refer to Check the RF part (P.42).
  • Page 48: Check Bt Communication

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 10.1.12. Check BT Communication Plug in the AC power source and wait 10 seconds. Use a handset to enter the "Bluetooth" menu: Press [MENU] Bluetooth [SELECT] Is it possible to enter the "Bluetooth" menu? Check the circuit of around RF parts of BT Is it possible to register BT_Headset? Module Check Voice Transmission of the BT_Headset...
  • Page 49 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Case1: OK AC power on PIO01 0.05s 1.95s 1.5s Case2: NG1(fail to reset BT_IC) AC power on If BT_IC does not work, 1st and 2nd signals does not appear. Check the circuit of around PIO01 POWER and RESET parts of BT Module.
  • Page 50: Disassembly And Assembly Instructions

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 11 Disassembly and Assembly Instructions 11.1. Disassembly Instructions 11.1.1. Base Unit Remove the 5 screws to remove the cabinet cover. Remove the solders. Cabinet cover Solders Remove the pararell wire to remove the main P.C. board.
  • Page 51 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Remove the 2 screws to remove the Jack holder. Remove the 4 screws to remove the operational P.C.B board.
  • Page 52: Handset

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 11.1.2. Handset 2 screws Remove the 2 screws. Insert a JIG (PQDJ10006Y) between the cabinet body Cabinet body and the cabinet cover, then pull it along the gap to open the cabinet. Cabinet cover Likewise, open the other side of the cabinet. Cabinet cover Remove the cabinet cover by pushing it upward.
  • Page 53: Charger Unit

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 11.1.3. Charger Unit 2 charge terminals...
  • Page 54: How To Replace The Base Unit Lcd

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 11.2. How to Replace the Base unit LCD Fit the heatseal of a new LCD. Vertical Interval Tolerance 0.2mm Horizontal Interval Tolerance 0.2mm If interval tolerance between center lines is less than 0.2 mm, it is o.k. New LCD Operational P.C.B.
  • Page 55 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Attach the LCD and fix by hook A (two points). Solder the wires.
  • Page 56: How To Replace The Handset Lcd

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 11.3. How to Replace the Handset LCD Note: The illustrations are simplified in this page. They may differ from the actual product. P. C. board Vertical Interval Tolerance Peel off the FFC (Flexible Flat Cable) from 0.2 mm the LCD, in the direction of the arrow. Take care to ensure that the foil on the P.C.
  • Page 57: Measurements And Adjustments

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12 Measurements and Adjustments This chapter explains the measuring equipment, the JIG connection, and the PC setting method necessary for the measurement in Troubleshooting Guide (P.34) 12.1. Equipment Required • Digital multi-meter (DMM): it must be able to measure voltage and current. •...
  • Page 58: Connections (Handset)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.2.2. Connections (Handset) Connect the DC Power or Battery to BATT+ and BATT-. Connect the JIG cable GND (black) to GND. Connect the JIG cable UTX (yellow) to UTX and URX (red) to URX. URX (red) To Serial Port UTX (yellow) (com port 1*) GND (black)
  • Page 59: How To Install Batch File Into P.c

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.2.3. How to install Batch file into P.C. Insert the Batch file CD-ROM into CD-ROM drive and copy PNZZTG**** folder to your PC (example: D drive). <Example for Windows> On your computer, click [Start], select Programs Open an MS-DOS mode window. (All Programs for Windows XP/Windows Server 2003), then click MS-DOS Prompt.
  • Page 60: Commands

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.2.4. 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” to “FF” is read out. readid Read ID (RFPI) Type “readid”, and the registered ID is read out.
  • Page 61: Adjustment Standard (Base Unit)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.3. Adjustment Standard (Base Unit) When connecting the simulator equipment for checking, please refer to below. 12.3.1. Bottom View Oscilloscope Oscilloscope Volt SPN SPP UART Meter D472 D473 C660 C653 C654 C669 C668 C655 C658 C652 C659 C667 C656 C657 C651 RA721 TP_ANT_BT...
  • Page 62: Adjustment Standard (Handset)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.4. Adjustment Standard (Handset) When connecting the simulator equipment for checking, please refer to below. 12.4.1. Component View ANT-Short ANT-Short-GND ANT1 RECEIVER PNLB2159Z -GW KX-TGA680 C70 C71 C809 CKM/STM C807 ATSTN C803 ATSTP L802 C804 RSTN C802 GND_J 3.0V RF-SHIELD VDDC CHG_CUR...
  • Page 63: Things To Do After Replacing Ic Or X'tal

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.5. Things to Do after Replacing IC or X'tal If repairing or replacing EEPROM and X'tal, it is necessary to download the required data such as Programming data or adjustment data, etc. in memory. The set doesn't operate if it is not executed. 12.5.1.
  • Page 64 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK Items How to download/Required adjustment BBIC(IC501) Programming data is stored in memory. 1) Clock adjustment: Refer to Check Point (H).(*2) EEPROM (IC611) Adjusted parameter data is stored in memory. 1) Change the address “0001” of EEPROM to “AA” to download (country version batch file, default batch file, the data.
  • Page 65 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.5.1.2. Handset First, operate the PC setting according to The Setting Method of JIG (P.57). Then download the appropriate data according to the following procedures. Items How to download/Required adjustment EEPROM (IC3) Adjusted parameter data is stored in memory. 1) Default batch file: Execute the command “default.bat”.
  • Page 66: Frequency Table

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.6. Frequency Table Ch. (hex) TX/RX Frequency (MHz) Channel 0 1928.448 Channel 1 1926.720 Channel 2 1924.992 Channel 3 1923.264 Channel 4 1921.536...
  • Page 67: Bluetooth Frequency Table

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 12.7. Bluetooth Frequency Table Frequency (MHz) Frequency (MHz) Frequency (MHz) 2402 2435 2468 2403 2436 2469 2404 2437 2470 2405 2438 2471 2406 2439 2472 2407 2440 2473 2408 2441 2474 2409 2442 2475 2410 2443 2476 2411 2444 2477 2412 2445...
  • Page 68: Miscellaneous

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 13 Miscellaneous 13.1. How to Replace the LLP (Leadless Leadframe Package) IC Note: This description only applies to the model with Shield case. 13.1.1. 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.
  • Page 69: How To Install The Ic

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 13.1.4. How to Install the IC 1. Place the solder a little on the land where the radiation GND pad on IC bottom is to be attached. Soldering Iron Land Solder P.C.Board 2. Place the solder a little on the land where IC pins are to be attached, then place the IC. Note: •...
  • Page 70: How To Replace The Flat Package Ic

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 13.2. 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. 13.2.1.
  • Page 71: How To Install The Ic

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 13.2.3. 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 72: Terminal Guide Of The Ics, Transistors And Diodes

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 13.3. Terminal Guide of the ICs, Transistors and Diodes 13.3.1. Base Unit (Reverse View) PNWI1TG7841H (*1) PNWI1TG7871H (*2) PNWI2TG7871H C0DBEYY00102 C1CB00003663 PNWI3TG7871H B1ACGP000008 DSC7003S0L Cathode Anode Cathode Anode B1ABDM000001, B1ADGE000012 DA2J10100L B1ADNB000003, 2SC6054JSL DY2J25000L B0ECKM000008 B1ADCF000040, B1GBCFGA0021 B0JCDD000001 B0EDER000009 B0BC4R3A0006 2SA1576S, B1GBCFYY0020 Cathode...
  • Page 73: Schematic Diagram

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 14 Schematic Diagram 14.1. For Schematic Diagram 14.1.1. Base Unit (Schematic Diagram (Base Unit_Main)) Notes: 1. DC voltage measurements are taken with voltmeter from the negative voltage line. Important Safety Notice: Components identified by mark have special characteristics important for safety.
  • Page 74: Schematic Diagram (Base Unit_Main)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 14.2. Schematic Diagram (Base Unit_Main) +5.5V C451 C452 Q661 R661 WBX02 13pin C458 0.033u Q663 PARALLEL WIRE SP Phone Tx +3.0_CP2 R664 C457 0.033u +3.0_CP2 C661 Q662 0.1u SP Phone Rx C459 SPI2_DO LCD_SIO 1000p C460 C473 +1.8V LCD_VDD LCD_GND LCD_BLT C472...
  • Page 75 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Q141 R160 REFERENCE 1XX : TEL LINE 3XX : POWER, CHARGE Q161 4XX : MIC, SP R141 5XX : BBIC 6XX : FLASH, EEPROM, KEY, LCD 100k 7XX : FOR DK/BT C163 NC 8XX : RF C173 R164 R161 2.7k 100k 0.1u...
  • Page 76: Schematic Diagram (Base Unit_Rf)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 14.3. Schematic Diagram (Base Unit_RF) ANT1_TP ANT2_TP C851 C853 ANT1-Short ANT2-Short ANT2-S-GND W 0.15mm W 0.15mm ANT1-S-GND L 22+/-4mm L 22+/-4mm 1st or 4th layer 1st or 4th layer RX-balun 50 ohm line W=0.175mm L=4mm L=2.7mm S=0.125mm RF_RXn *open-stub SLx2 W=0.25mm W1=0.2mm...
  • Page 77: Schematic Diagram (Base Unit_Operation)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 14.4. Schematic Diagram (Base Unit_Operation) LCD_Light KEY_PCB+ CN901 R906 C902 CN901 KEY_PCB- 1u 16V CN901 C901 VDDA CN901 CN901 CN901 SCLK CN901 CN901 RESETB CN901 LCD_CSB CN901 CN901 OPT_PWR LCD_SIO CN901 LCD_VDD LCD_GND LCD_BLT LCD_SCL LCD_CD 13pin:TG6841/TG7871 LCD_RST CELL1 CELL2 LCD_CS LED901...
  • Page 78: Schematic Diagram (Base Unit_Usb Charge)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 14.5. Schematic Diagram (Base Unit_USB Charge) F1001 3.0A USB_+5V CN1001 USB_GND FOR TG7871H NC: No Components KX-TG7841/7842/7843/7844/7845/365/7871/7872/7873/7874/7875/385 SCHEMATIC DIAGRAM (Base Unit_USB Charge) 14.6. Schematic Diagram (Base Unit_LED) KX-TG7841/7842/7843/7844/7845/365/7871/7872/7873/7874/7875/385 SCHEMATIC DIAGRAM (Base Unit_LED)
  • Page 79 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Memo...
  • Page 80: Schematic Diagram (Handset_Main)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 14.7. Schematic Diagram (Handset_Main) VBAT Charge Current BAT+ 2.5A BAT- Battery CHG_CUR R10 1.0 CP3V When on Charge Battery_ON 0.1u * Start Monitor 1000p 3.3k EEP_WP * When "SFR" command CHG+ EEP_SCL is executed, 13.824MHz EEP_SDA CHG+ frequency will be output. CHARGE Terminal TO RF BLOCK...
  • Page 81 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 RF BLOCK ANT-Pattern ANT-Short Wm=0.4mm C808 Lm=10mm 1.3p C801 ANT1 ANT-Short-GND SHORT1 W=0.3mm W=0.3mm W=0.3mm W=0.25 W 0.2mm L=12.45mm L=6.95mm L=6.5mm W 0.15mm L=2mm L 3.8mm L 6.2mm 1st layer 1st layer Tx-balun open-stub open-stub W=0.3 W=0.2mm L=40mm W=2.9mm W=0.25 L=20mm W=2.2mm...
  • Page 82 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Memo...
  • Page 83: Printed Circuit Board

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 15 Printed Circuit Board 15.1. Circuit Board (Base Unit_Main) 15.1.1. Component View R663 R664 R721 C455 C479 C457 C476 C458 C454 RA654 C506 C109 R475 R109 R474 C174 R110 C459 C461 C473 C472 C172 C110 C124 C123 C510 C512 R121 C505 X501...
  • Page 84: Bottom View

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 15.1.2. Bottom View SPN SPP For JIG RA721 ANT_BT ANT_TP-BT C731 Q731 TP_ANT_BT R736 BT_URX BT_TDO Q732 BT_GND BT_UTX BT_SIO BT_SOT BT_MDO +5.5V R667 R721 RA653 R105 R103 STM/CKM/P15 C451 STM/CKM/P15 CHARGE- C107 (CLK:13.824MHz) Q301 D361 C108 R104 C519 R702 C351 R311...
  • Page 85: Circuit Board (Base Unit_Operation)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 15.2. Circuit Board (Base Unit_Operation) C912 KX-TG7841/7842/7843/7844/7845/365/7871/7872/7873/7874/7875/385 CIRCUIT BOARD (Base Unit_Operation (Component View))
  • Page 86: Circuit Board (Base Unit_Usb Charge)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 15.3. Circuit Board (Base Unit_USB Charge) PNLB2177Z -IG R1004 R1002 F1001 R1003 R1001 KX-TG7841/7842/7843/7844/7845/365/7871/7872/7873/7874/7875/385 CIRCUIT BOARD (Base Unit_USB (Component View)) 15.4. Circuit Board (Base Unit_LED) PNLB1964Z KX-TG7841/7842/7843/7844/7845/365/7871/7872/7873/7874/7875/385 CIRCUIT BOARD (Base Unit_LED (Component View))
  • Page 87: Circuit Board (Handset_Main)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 15.5. Circuit Board (Handset_Main) 15.5.1. Component View ANT-Short ANT-Short-GND ANT1 RECEIVER PNLB2159Z -GW KX-TGA680 C70 C71 C809 CKM/STM C807 CKM/STM ATSTN C803 ATSTP (CLK:13.824MHz) RSTN L802 C804 C802 GND_J 3.0V (Output) 3.0V RF-SHIELD VDDC CHG_CUR VBG/CHG_MON MIC+ MIC+ MIC- MIC- CHG_CTRL CHG_DET...
  • Page 88: Bottom View

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 15.5.2. Bottom View CN3_C SOFT_A SOFT_C LEFT RIGHT LED5 LED4 LED2 LED3 SHARP LED6 LED1 FLASH KX-TGA680 CIRCUIT BOARD (Handset_Main (Bottom View))
  • Page 89: Exploded View And Replacement Parts List

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16 Exploded View and Replacement Parts List 16.1. Cabinet and Electrical Parts (Base Unit) E1 (*1) PCB1 PCB2 MIC1 PCB3 (*3) 26 (*2) 19 (*3) Ref.No. Figure 2.6 x 8mm Note: (*1) This cable is fixed by heat-sealing. Refer to How to Replace the Base unit LCD (P.54). (*2) KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK (*3) KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK...
  • Page 90: Cabinet And Electrical Parts (Handset)

    (*1) This cable is fixed by heat-sealing. Refer to How to Replace the Handset LCD (P.56). (*2) The rechargeable Ni-MH battery HHR-4DPA is available through sales route of Panasonic. (*3) Attach the SPACER (No. 118) to the exact location described above.
  • Page 91: Cabinet And Electrical Parts (Charger Unit)

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.3. Cabinet and Electrical Parts (Charger Unit) 200-1 200-5 200-2 200-2 200-3 200-4...
  • Page 92: Accessories And Packing Materials

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4. Accessories and Packing Materials 16.4.1. KX-TG7841S A3, A4...
  • Page 93: Kx-Tg7842S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.2. KX-TG7842S A101 A102 P102 P102 (*1) P102 A105 A103, A104 P101 Note: (*1) This pad is a piece of Ref No.P101 (GIFT BOX).
  • Page 94: Kx-Tg7843S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.3. KX-TG7843S P202 P202 P202 P202 A202 P202 P202 A201 A205 P202 A203, A204 P201...
  • Page 95: Kx-Tg7844S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.4. KX-TG7844S P302 P302 P302 P302 A301 P302 P302 P302 P302 A302 A303, A304 A305 P301...
  • Page 96: Kx-Tg7845S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.5. KX-TG7845S P402 P402 P402 P402 P402 P402 P402 P402 P402 A402 A401 P402 A403, A404 A405 P401...
  • Page 97: Kx-Tg365Sk

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.6. KX-TG365SK A503, A504 A501 A502 A505...
  • Page 98: Kx-Tg7871S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.7. KX-TG7871S P602 P602 P602 P602 A601 P602 P602 A605 A603, A604 A602 P601...
  • Page 99: Kx-Tg7872S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.8. KX-TG7872S A701 (*1) A702 P702 P702 (*1) P702 A705 A703, A704 P701 Note: (*1) This pad is a piece of Ref No.P701 (GIFT BOX).
  • Page 100: Kx-Tg7873S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.9. KX-TG7873S P802 A801 A802 (*1) P802 P802 A805 P802 P802 P802 P802 A803, A804 P801 Note: (*1) This pad is a piece of Ref No.P801 (GIFT BOX).
  • Page 101: Kx-Tg7874S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.10. KX-TG7874S P902 P902 P902 A901 (*1) P902 P902 A902 A903, A904 A905 P901 Note: (*1) This pad is a piece of Ref No.P901 (GIFT BOX).
  • Page 102: Kx-Tg7875S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.11. KX-TG7875S P1002 P1002 A1002 P1002 P1002 (*1) A1001 P1002 P1002 P1002 P1002 P1002 P1002 A1005 A1003, A1004 P1001 Note: (*1) This pad is a piece of Ref No.P1001 (GIFT BOX).
  • Page 103: Kx-Tg385Sk

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.12. KX-TG385SK A1103, A1104 A1101 A1102 A1105...
  • Page 104: Kx-Tga680S

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.4.13. KX-TGA680S A1202 (*1) P1202 A1201 P1201 Note: (*1) This pad is a piece of Ref No.P1201 (GIFT BOX).
  • Page 105: Replacement Parts List

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.5. Replacement Parts List Safety Ref. Part No. Part Name & Description Remarks 1. RTL (Retention Time Limited) PQHR11082Z GUIDE, SPEAKER POM-HB PNKE1272Z2 CASE, CHARGE TERMINAL PS-HB Note: PNJT1144Z CHARGE TERMINAL The “RTL” marking indicates that its Retention Time is PNBC1486Z1 BUTTON, NAVIGATOR KEY ABS-HB...
  • Page 106 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 16.5.1.2. Main P.C. Board Parts Safety Ref. Part No. Part Name & Description Remarks Note: RA653 D1H810240004 RESISTOR ARRAY (*1) When replacing IC501, IC502, IC601, IC611 or X501, RA654 D1H810240004 RESISTOR ARRAY make the adjustment using PNZZTG7871M. Refer to How RA655 EXB28V473JX RESISTOR ARRAY...
  • Page 107: Handset

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Safety Ref. Part No. Part Name & Description Remarks Safety Ref. Part No. Part Name & Description Remarks R735 ERJ2RKF4702 PNHX1617Z COVER, REFLECTOR SHEET R736 ERJ2GEJ223 PNHR1761Z GUIDE, LCD ABS-HB R738 ERJ2RKF3302 P101 D4DAY220A022 THERMISTOR (POSISTOR) R891 D0GA221JA021 220 F301 K5H302Y00003 FUSE R892...
  • Page 108 KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Safety Ref. Part No. Part Name & Description Remarks Safety Ref. Part No. Part Name & Description Remarks PNQT2006Z LABEL, ATTENTION ERJ2GEYJ391 PNQT2629Z LABEL, BATTERY ERJ2GEJ100 PNHS1466Z SPACER, BATTERY D0GA222JA021 2.2k PNKK1076Z1 LID, BATTERY ABS-HB D0GA332JA015 3.3k PNYNTGA680BR LID, BATTERY ASS'Y ABS-HB D0GA222JA021 2.2k PNHR1644Z...
  • Page 109: Charger Unit

    INSTRUCTION BOOK (*1) Instructions (Instruction book) on TSN Server. A504 PNQW3431Z LEAFLET, QUICK GUIDE A505 PNKE1268Z1 HANGER, BELT CLIP ABS-HB 16.5.4.1. KX-TG7841S 16.5.4.7. KX-TG7871S Safety Ref. Part No. Part Name & Description Remarks Safety Ref. Part No. Part Name & Description Remarks...
  • Page 110: Screws

    KX-TG7841/KX-TG7842/KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680 Safety Ref. Part No. Part Name & Description Remarks Safety Ref. Part No. Part Name & Description Remarks A802 PQJA10075Z CORD, TELEPHONE PNZZTG7871M BATCH FILE CD-ROM (*1) A803 PNQX5764Z INSTRUCTION BOOK (*1) PQZZ430PIR TIP OF SOLDERING IRON (*2) A804 PNQW3431Z LEAFLET, QUICK GUIDE PQZZ430PRB...
  • Page 111 Solution B: Black Version S: Silver Version (for U.S.A.) Please file and use this supplement manual together with the service manual for Model No.KX-TG7841S/ KX-TG7842S/KX-TG7843S/KX-TG7844S/KX-TG7845S/KX-TG365SK/KX-TG7871S/KX-TG7872S/KX- TG7873S/KX-TG7874S/KX-TG7875S/KX-TG385SK/KX-TGA680S/KX-TGA20B, Order No. KM41302655CE. © Panasonic System Networks Co., Ltd. 2014 Unauthorized copying and distribution is a violation...
  • Page 112 KX-TG7841/KX-TG7842KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680/KX-TGA20 TABLE OF CONTENTS PAGE 1 REPLACEMENT PARTS LIST ---------------------------------3 1.1. REFERENCE CHART ------------------------------------3 1.2. ORIGINAL AND NEW PARTS COMPARISON LISTS ------------------------------------3...
  • Page 113 Part Name & Description Pcs/ Remarks Notes Time of Change Original (Old) (Suffix) Cabinet and Electrical Parts (Base Unit) PNGT7152Z PNGT7732Z NAME PLATE (for KX-TG7841S/ TG7842S/TG7843S/TG7844S/ TG7845S/TG365SK) PNGT7261Z PNGT7677Z NAME PLATE (for KX-TG7871S/ TG7872S/TG7873S/TG7874S/ TG7875S/TG385SK) (Made in China) ---------- PNGT7854Z...
  • Page 114 KX-TG7841/KX-TG7842KX-TG7843/KX-TG7844/KX-TG7845/KX-TG365SK/KX-TG7871/KX-TG7872/KX-TG7873/KX-TG7874/KX-TG7875/KX-TG385SK/KX-TGA680/KX-TGA20 KXTG7841S KXTG7842S KXTG7843S KXTG7844S KXTG7845S KXTG365SK KXTG7871S KXTG7872S KXTG7873S KXTG7874S KXTG7875S KXTG385SK KXTGA680S KX-TGA20B...

Table of Contents