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Panasonic KX-TG8421FXB Service Manual

Manual is about: Digital

Summary of KX-TG8421FXB

  • Page 1

    © panasonic communications co., ltd. 2009. Unauthorized copying and distribution is a violation of law. Order no. Km40903862ce telephone equipment model no. Kx-tg8421fxb kx-tg8421fxn kx-tga840fxb kx-tga840fxn digital cordless answering system b:black version n:platinum silver version (for central eu...

  • Page 2

    2 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn.

  • Page 3: Table of Contents

    3 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn table of contents page page 1 safety precautions----------------------------------------------- 4 1.1. For service technicians --------------------------------- 4 2 warning -------------------------------------------------------------- 4 2.1. Bat...

  • Page 4: 1 Safety Precautions

    4 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 repai...

  • Page 5

    5 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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). P...

  • Page 6: 3 Specifications

    6 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 • op...

  • Page 7: 4 Technical Descriptions

    7 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 4 technical descriptions 4.1. Block diagram (base unit) analog front end t o tel_line bridge rect d3d3 hook switch q4,q5 audio bell/caller id interface cpu 18 16 23 20 21 19 24 bell hook off-hook line voltage 25 a/d d/a adpcm codec filter dsp spe...

  • Page 8

    8 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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...

  • Page 9

    9 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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....

  • Page 10

    10 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 4.2.3. Telephone line interface • 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 curren...

  • Page 11

    11 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 4.3. Block diagram (handset) speaker receiver mic mic det sp headset charge circuit q4, q9, r7q4, q9, r7 charge contacts charge(+) charge(-) charge_ctrl charge eeprom scl sda battery terminal d7 vbat j1 j2 1.8 v q2 1.8 v lcd cd reset csb sda scl...

  • Page 12

    12 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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,...

  • Page 13

    13 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 4.5. Circuit operation (charger unit) 4.5.1. Power supply circuit the power supply is as shown..

  • Page 14

    14 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 4.6. Signal route.

  • Page 15

    15 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn.

  • Page 16: 5 Location of Controls and

    16 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 5 location of controls and components 5.1. Controls 5.1.1. Base unit 5.1.2. Handset.

  • Page 17: 6 Installation Instructions

    17 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 6 installation instructions 6.1. Connections 6.2. Battery 6.2.1. Battery installation see for service hint (p.28) 6.2.2. Battery charge.

  • Page 18

    18 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn note for service: the battery strength may not be indicated correctly if the battery is disconnected and connected again, even after it is fully charged. In that case, by recharging the battery as mentioned above, you will get a correct indicati...

  • Page 19: 7 Operating Instructions

    19 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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

    20 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn *1 the item will not be reset when pressing , , and keys. Refer to how to clear user setting (p.35). *2 the item will not be reset when pressing , , and keys. Refer to how to clear user setting (p.35). Cross reference: registering a handset to a...

  • Page 21

    21 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 7.1.2. Answering system setting 7.1.3. Sms settings.

  • Page 22

    22 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 7.2. Registering a handset to a base unit if you forget your pin, see for service hint (p.28) note: • when you purchase an additional handset, refer to the additional handset's installation manual for registration. 7.2.1. Deregistering a handset...

  • Page 23

    23 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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. 7.3.1. Copying all entries 7.4. Dialling mode 7.5. Error mess...

  • Page 24

    24 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 7.6. Troubleshooting.

  • Page 25

    25 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn cross rreference: for service hint (p.28).

  • Page 26

    26 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn.

  • Page 27

    27 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn.

  • Page 28

    28 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 7.7. For service hint cross reference: battery charge (p.17).

  • Page 29: 8 Service Mode

    29 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 8 service mode 8.1. Engineering mode 8.1.1. Base unit.

  • Page 30

    30 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn frequently used items (base unit) ex.) note: (*1) refer to registering a handset to a base unit (p.22). (*2) when you enter the address or new data, please refer to the table below. (*3) items address default data new data remarks c-id (fsk) sen...

  • Page 31

    31 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 8.1.2. Handset.

  • Page 32

    32 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn frequently used items (handset) ex.) note: (*1) when you enter the address or new data, please refer to the table below. (*2) when adding “01” (hex) to default value, sending level increases by 0.25 db. Ex.) (*3) when reducing “01” (hex) from de...

  • Page 33

    33 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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-tg8411/8412/8421...

  • Page 34

    34 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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) • to cancel the handse...

  • Page 35

    35 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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). • the...

  • Page 36: 9 Troubleshooting Guide

    36 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 re...

  • Page 37

    37 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 9.1.1. Check power 9.1.1.1. Base unit is the ac adaptor inserted into ac outlet? (*1) cross reference: power supply circuit (p.9) note: (*1) refer to specifications (p.6) for part number and supply voltage of ac adaptor. 9.1.1.2. Handset cross r...

  • Page 38

    38 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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

    39 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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

    40 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn cross reference: check point (base unit) (p.48).

  • Page 41

    41 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 9.1.3.2. Handset cross reference: check point (handset) (p.52) power supply circuit/reset circuit (p.12).

  • Page 42

    42 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn cross reference: check point (handset) (p.52).

  • Page 43

    43 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 re...

  • Page 44

    44 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 che...

  • Page 45

    45 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 9.1.4.3. Check table for rf part note: (*1) refer to adjustment standard (base unit) (p.63) (*2) refer to adjustment standard (handset) (p.67) no. Item bu (base unit) check hs (handset) check 1 link confirmation normal hs, bu mode: [normal mode]...

  • Page 46

    46 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 ...

  • Page 47

    47 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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....

  • Page 48

    48 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 ...

  • Page 49

    49 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn (h)* hookswitch check with dc characteristics - 1. Connect telephone socket to tel-simulator which is connected with 600 Ω. 2. Set line voltage to 48 v and line current to 40ma at off-hook condition of nor- mal telephone. 3. Execute the command ...

  • Page 50

    50 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn (m)* frequency drift confir- mation - anti_tp follow steps 1 to 6 of (j). 7.Confirm that the frequency drift is ic7, c802~c806, c808~c814, c820, c819, c822, c823, c825, c827, c826, c834, c851, c853, c859~c861, da801, da802, ic801, l801~l803, c85...

  • Page 51

    51 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 9.2.2. Check point (charger unit) note: after the measuring, suck up the solder of tp. The connection of adjustment equipment is as shown in adjustment standard (charger unit) (p.64). (q) audio check - 1. Link with handset. 2. Input -45dbm/1khz ...

  • Page 52

    52 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 ...

  • Page 53

    53 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn (f)* battery monitor check - 1. Apply 2.25 v between batt+ and batt-. 2. Execute the command sendchar pad sendchar led 0 sendchar crx 0 1 sendchar ad1 it assumes that the return value is xx. A) 6c xx 71: no need to adjust b) xx: 6a ~ 6b: need to...

  • Page 54

    54 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn (k)* frequency offset confir- mation - follow steps 1 to 3 of (i). 4.Confirm that the frequency offset is ic1, c802~c806, c808~c814, c819~c820, c822, c825~c827, c834, c859~c864, l801~l804, da801, r801~r808 (l)* frequency drift confir- mation - f...

  • Page 55

    55 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 som...

  • Page 56

    56 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 10 disassembly and assembly instructions 10.1. Disassembly instructions 10.1.1. Base unit.

  • Page 57

    57 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn.

  • Page 58

    58 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 10.1.2. Handset.

  • Page 59

    59 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 10.1.3. Charger unit.

  • Page 60

    60 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 10.2. How to replace the handset lcd.

  • Page 61

    61 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11 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.36) 11.1. Equipment required • digital multi-meter (dmm): it m...

  • Page 62

    62 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.2.2. How to install batch file into p.C. Note: • “*****” varies depending on the country or models. 11.2.3. Commands see the table below for frequently used commands. Command name function example rdeeprom read the data of eeprom type “rdeepr...

  • Page 63

    63 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.3. Adjustment standard (base unit) when connecting the simulator equipments for checking, please refer to below. 11.3.1. Bottom view note: (a) - (t) is referred to check point (base unit) (p.48) a pnlb1100z chg sp l2t l1t l1r l2r 1 80 e e e 1...

  • Page 64

    64 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.4. Adjustment standard (charger unit) when connecting the simulator equipment for checking, please refer to below. 11.4.1. Bottom view note: (a) is referred to check point (charger unit) (p.51) tp4 tp3 1 2 j1 d1 a f1 pbf pqlv30055 pqlv30056 p...

  • Page 65

    65 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.5. The setting method of jig (handset) this section explains the pc setting to use command required in check point (handset)(p.52). • serial jig cable: pqzz1cd300e* • pc which runs in dos mode • batch file cd-rom for setting: pnzztg8421fx not...

  • Page 66

    66 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.5.2. How to install batch file into p.C. Note: • “*****” varies depending on the country or models. 11.5.3. Commands see the table below for frequently used commands. Command name function example rdeeprom read the data of eeprom type “rdeepr...

  • Page 67

    67 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.6. Adjustment standard (handset) when connecting the simulator equipments for checking, please refer to below. 11.6.1. Component view note: (a) - (r) is referred to check point (handset) (p.52) a pbf pnlb1104z kx-tga840xx eu c138 c71 c152 c70...

  • Page 68

    68 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.7. Things to do after replacing ic or x'tal if repairing or replacing bbic (flash type), eeprom and x'tal, it is necessary to download the required data such as program- ming data or adjustment data, etc in memory. The set doesn't operate if ...

  • Page 69

    69 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.7.1.2. Handset first, operate the pc setting according to the setting method of jig (handset)(p.65). Then download the appropriate data according to the following procedures. Note: (*3) xx: country code, yy: revision number “xx” and “yy” vary...

  • Page 70

    70 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.8. Rf specification 11.8.1. Base unit *: refer to check point (base unit) (p.48) 11.8.2. Handset **: refer to check point (handset) (p.52) item value refer to -. * tx power 19 dbm ~ 25 dbm check point (base unit) (j) modulation -370±30/+370±3...

  • Page 71

    71 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 11.9. 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. 11.10. Frequency table (mhz) note: channel no. 10: in the tes...

  • Page 72: 12 Miscellaneous

    72 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 12 miscellaneous 12.1. Cpu data (base unit) 12.1.1. Ic7 (bbic) pin no. Description i/o connection at normal mode at reset mode 1 vss_lna1 - gnd - - 2 rf_rxp a.I rf_rxp a.I a.I 3 rf_rxn a.I rf_rxn a.I a.I 4 vss_lna2 - gnd - - 5 rfp1 d.O rxon o_0/...

  • Page 73

    73 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 59 p0_1/urx d.I urx i_0/1 - 60 p0_0/utx d.O utx o_0/1 - 61 rstn d.O rstn o_0/1 o 62 jtag d.I/o jtag i/o_0/1 i-pu 63 p2_5/pcm_fsc/sf d.O eep_wp o_0 o_0 64 p2_4/scl1/pcm_do/ dp3 d.O test o_0 o-0 65 p2_3/sda1/pcm_di/dp2 d.O n.C. O_0 o-0 66 p2_2/pcm...

  • Page 74

    74 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 12.2. Cpu data (handset) 12.2.1. Ic1 (bbic) pin no. Description i/o connection at normal mode at reset mode 1 vss_lna1 - gnd - - 2 rf_rxp a.I rf_rxp a.I a.I 3 rf_rxn a.I rf_rxn a.I a.I 4 vss_lna2 - gnd - - 5 rfp1 d.O rxon o_0/1 l 6 rfp0 d.O ant1...

  • Page 75

    75 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 62 jtag d.I/o jtag d.I/o i-pu 63 p2_5/pcm_fsc/sf d.O lcd_csb d.O i-pu 64 p2_4/scl1/pcm_do/ dp3 - n.C. - l 65 p2_3/sda1/pcm_di/dp2 - n.C. - l 66 p2_2/pcm_clk/clk100 d.O lcd_reset d.O l 67 p2_1/ecz2/pwm1/led4 - n.C. - - 68 p2_0/ecz1/pwm0/led3 d.I ...

  • Page 76

    76 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 ...

  • Page 77

    77 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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. Solder the pin...

  • Page 78

    78 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 t...

  • Page 79

    79 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 12.4.4. How to install the shield case note: • if you don’t have special tools (ex. Hot air disordering tool), conduct the following operations. • shield case’s no. : pnmc1013z 1. Put the shield case. 2. Solder the surroundings..

  • Page 80

    80 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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: 13 Schematic Diagram

    81 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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 w...

  • Page 82

    82 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 13.2. Schematic diagram (base unit) 3.0v 2.5v tx _rf tx _rf rx _rf beep bell signal gnd spm spp gnd gnd gnd *c505 nc *c502 nc *sw1 nc 1 2 gnd nc *c501 gnd +3.0v 100 r75 270k *r425 utx urx gnd ant_1 ant2 nc c854 ant1 gnd gnd ant_2 gnd nc c850 gnd...

  • Page 83

    83 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 1.8v 3.0v tx _rf rx _rf tx _af bell signal caller id 0.75v 0v 250mvp-p loop current charge current rx_af bell signal gnd gnd q8 1u c614 gnd +1.8v gnd gnd gnd gnd 56k f r615 gnd gnd gnd sa1 l1 l2 gnd gnd j101 gnd gnd +8.0v k2.2u c31 gnd 4 fin 1 a...

  • Page 84

    84 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 13.3. Schematic diagram (base unit_operation) ans1 1 2 stop 1 2 erase 1 2 msg2 1 2 msg1 1 2 rpt 1 2 skip 1 2 up 1 2 down 1 2 locat/int 1 2 led902 a k led901 a k meg_led keyin2 keys_b ans_led keys_e keys_c keyin1 2apvcc keyin3 keys_d pcb kx-tg842...

  • Page 85

    85 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn memo.

  • Page 86

    86 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 13.4. Schematic diagram (handset) batt+ batt- 0.1 r45 battery gnd chg(+) chg(-) r65 ( ) 1k r66 5.6n f1 d8 ( ) 100 r63 c36 ( ) c45 k0.1u c121 ( ) c35 ( ) c15 ( ) +1.8v 3.3k r22 gnd k1u c47 w_led- w_led+ gnd gnd gnd gnd gnd gnd gnd gnd gnd gnd gnd...

  • Page 87

    87 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn +1.8v cn4 headset jack 1 4 2 3 5 100k r32 mic- mic+ receiver + - sp-phone_speaker + - r100 ( ) d10p c71 d10p c83 d10p c72 d10p c73 d10p c113 c128 ( ) c108 ( ) c82 k470p k0.1u c172 l72 10k r40 10k r41 gnd battery r152 ( ) gnd gnd 0 r208 0 r209 c1...

  • Page 88

    88 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 13.5. Schematic diagram (charger unit) j1 2 1 tp3 g tp2 tp1 tp4 r1 10 d1 a k f1 schematic diagram (charger unit).

  • Page 89: 14 Printed Circuit Board

    89 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 14 printed circuit board 14.1. Circuit board (base unit_main) 14.1.1. Component view c519 c520 c518 c517 c511 c512 c513 c514 c515 c516 c8 c4 c43 c17 c16 c15 c28 c25 c27 c42 c3 c2 c1 c861 c860 c811 c806 c827 c825 c822 c163 c812 c804 c803 c850 c85...

  • Page 90

    90 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 14.1.2. Bottom view kx-tg8421 circuit board (base unit_main (bottom view)) a pnlb1100z chg sp l2t l1t l1r l2r 1 80 e e e 1 clk vdd5 vdd4 vdd3 vdd2 utx j101 red wht red blk gnd ant1_tp cl1 jt a g urx 4 e dc pbf c421 c422 c631 c625 c72 c137 c53 c5...

  • Page 91

    91 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 14.2. Circuit board (base unit_operation) 14.2.1. Component view erase stop keys_e keys_c keys_b meg_led keyin2 keys_d keyin3 keyin1 ans_led 2apvcc ans1 locat/int a down led902 led901 skip msg1 msg2 rpt up kx-tg7431/8421/8431h pnlb1092z pbf kx-t...

  • Page 92

    92 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 14.3. Circuit board (handset) 14.3.1. Component view kx-tga840 circuit board (handset_main (component view)) a pbf pnlb1104z kx-tga840xx eu c138 c71 c152 c70 receiver c139 speaker c29 c802 c72 c813 c811 c804 c73 c147 c121 c5 c3 f1 c76 c77 c113 c...

  • Page 93

    93 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 14.3.2. Bottom view 1 sp r 2 5 sw1 s1 talk soft_c soft_a 3 4 6 7 carbon_cl1 mic- mic+ mic 8 9 led6 led3 led5 led2 led12 w_led- w_led+ led1 led4 0 # kx-tga840 circuit board (handset_main (bottom view)) cn3 1 18 c102 c100 c104 c106 c107 c103 c27 c...

  • Page 94

    94 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 14.4. Circuit board (charger unit) 14.4.1. Component view 14.4.2. Bottom view j1 r1 d1 a pqup11532z pbf pqlv30055 pqlv30056 circuit board (charger unit (component view) ) tp4 tp3 1 2 j1 d1 a f1 pbf pqlv30055 pqlv30056 pqup11532z circuit board (c...

  • Page 95

    95 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 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) ...

  • Page 96

    96 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.2. Cabinet and electrical parts (handset) note: (*1) this cable is fixed by welding. Refer to how to replace the handset lcd (p.60). (*2) the rechargeable ni-mh battery p03p, hhr-4mre, or hhr-4mpt is available through sales route of panasonic...

  • Page 97

    97 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.3. Cabinet and electrical parts (charger unit).

  • Page 98

    98 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.4. Accessories and packing materials 15.4.1. Kx-tg8421fxb/fxn.

  • Page 99

    99 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.4.2. Kx-tga840fxb/fxn.

  • Page 100

    100 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.5. Replacement part list 1. Rtl (retention time limited) note: the “rtl” marking indicates that its retention time is limited. When production is discontinued, this item will con- tinue to be available only for a specific period of time. Thi...

  • Page 101

    101 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn d23 ma8220 diode(si) s d26 manv250gel diode(si) da801 b0ddcd000001 diode(si) da802 b0ddcd000001 diode(si) (coils) l1 pqlqxf330k coil s l2 pqlqxf330k coil s l801 g1c27nj00010 coil l802 g1c3n0za0063 coil l803 g1c3n0za0063 coil (component parts) r...

  • Page 102

    102 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.5.1.3. Operational p.C.Board parts 15.5.2. Handset 15.5.2.1. Cabinet and electrical parts 15.5.2.2. Main p.C.Board parts note: (*1) reconfirm the model no. Written on the handset’s name plate when replacing pcb100. Because the model no. Of t...

  • Page 103

    103 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn safety ref. No. Part no. Part name & description remarks pcb100 pnwpga840fxr main p.C.Board ass'y (rtl) (*1) (ics) ic1 c1cb00002906 ic (bbic (flash)) (*2) (*5)(*6) ic3 pqwia130exrr ic (eeprom) (*2) ic801 c1cb00001842 ic (*5) (transistors) q2 b1...

  • Page 104

    104 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.5.3. Charger unit 15.5.3.1. Cabinet and electrical parts 15.5.3.2. Main p.C.Board parts 15.5.4. Accessories and packing materials note: (*1) you can download and refer to the operating instruc- tions (instruction book) on tsn server. 15.5.4....

  • Page 105

    105 kx-tg8421fxb/kx-tg8421fxn/kx-tga840fxb/kx-tga840fxn 15.5.6. Fixtures and tools note: (*1) see equipment required (p.61), and the setting method of jig (handset) (p.65). M.S kxtg8421fxb kxtg8421fxn kxtga840fxb kxtga840fxn safety ref. No. Part no. Part name & description remarks pqzz1cd300e jig ca...