Toshiba FT-7800A Service Manual
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Toshiba FT-7800A Service Manual

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FILE NO. 2B0-200012
SERVICE MANUAL
CORDLESS TELEPHONE
FT-7800A
PUBLISHED IN JAPAN, Jan., 2001

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  • Page 1 FILE NO. 2B0-200012 SERVICE MANUAL CORDLESS TELEPHONE FT-7800A PUBLISHED IN JAPAN, Jan., 2001...

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS ........................1 OPERATING CONTROLS ........................2 ALIGNMENT PROCEDURE ........................3 BLOCK DIAGRAMS ..........................7 SCHEMATIC DIAGRAMS ........................9 TROUBLESHOOTING HINTS ......................13 IC AND TRANSISTOR VOLTAGE CHART ..................20 SEMICONDUCTOR LEAD IDENTIFICATION ..................24 ELECTRICAL PARTS LOCATION ...................... 26 WIRING DIAGRAMS..........................

  • Page 3: Operating Controls

    OPERATING CONTROLS HANDSET CONTROLS BASE UNIT CONTROLS — 2 —...

  • Page 4: Alignment Procedure

    ALIGNMENT PROCEDURE Base Unit Transmitter Section Connections BASE Unit AF GEN. Test Point Power Meter DC IN TEL Line 1kHz 77.5mV 9V Jack Jack Test Point Frequency Counter AC 120V Adapter 60Hz Deviation Meter Preset a) Connect the AC adapter to the base unit while pressing the “PAGE” key, and keep pressing it continuously for approximate 2 seconds.
  • Page 5 Base Unit Connections AC Voltmeter BASE Unit RF SG Dummy Load (600-ohm) − − TEL Line Test Point Jack DC Voltmeter DC IN 9V Jack AF Terminal AC 120V AC Adapter 60Hz Preset a) Connect the AC adapter to the base unit while pressing the “PAGE” key, and keep pressing it continuously for approximate 2 seconds.
  • Page 6 Handset Unit Transmitter Section Connections HANDSET Unit AF GEN. Test Point Power Meter J601 Battery 1kHz 9mV MIC + Pin Connector Test Point Frequency Counter DC Power Supply Deviation DC 3.8V Meter Preset a) Connect DC power supply to battery connector on the handset unit. b) Turn the DC power supply ON while pressing “...
  • Page 7 Handset Unit Connections AC Voltmeter HANDSET Unit RF SG Dummy Load (150-ohm) − − Connector Test Point J601 DC Voltmeter DC Power Supply Battery Connector AF Terminal DC 3.8V Preset a) Connect DC power supply to battery connector on the handset unit. b) Turn the DC power supply ON while pressing “...

  • Page 8: Block Diagrams

    BLOCK DIAGRAMS Base Unit — 7 —...
  • Page 9 Handset — 8 —...

  • Page 10: Schematic Diagrams

    SCHEMATIC DIAGRAMS Base Unit — 9 — — 10 —...
  • Page 11 Handset — 11 — — 12 —...

  • Page 12: Troubleshooting

    TROUBLESHOOTING 1. The bell does not ring. When the PAGE SW of the See 2. The bell does not base is pressed, does the ring & page does not ring. ringer on the handset ring? When the TEL SG is joined Check IC4 and TEL network with the base to make bell circuit.
  • Page 13 2. The bell does not ring & page does not ring. See 3. The base and Can the base and handset handset cannot be be connected? connected. Press handset DIAL key When the key of the Check IC602. while in TALK MODE. handset is pressed, can the Can key touch sound be pulse output at pin 38 of...
  • Page 14 3. The base and handset cannot be connected. Check IC2 and its Check whether the base peripheral circuit. can be set in the test mode 1. Check the TX POWER and Check base RF unit (B350). the TX FREQUENCY on the base unit.
  • Page 15 Press the "3" key, check Check RT603, R626, R672, Check whether there is a whether deviation of the R673, R679, R680 and 250Hz data waveform at TX data is app. ±35 kHz Dev. C642. C717. Check handset RF unit (B850). Press the "6"...
  • Page 16 4. Cannot make a phone call (pulse). Preset: Press "FLASH" key for about 2 seconds, then press "#" key to enter "Pulse" mode. See 3. The base and Can the base and handset handset cannot be be connected? connected. While in TALK MODE, Check IC2.

  • Page 17: Voice Cannot Be Transmitted To Other Party (Outgoing Call)

    6. Voice cannot be transmitted to other party (outgoing call). See 3. The base and Can the base and handset handset cannot be be connected? connected. Apply the 1 kHz, 9 mV sine Check R621, R622, R691, waveform to MC601 + C636, C637, C712, C713 side, can the 1 kHz sine and their peripheral circuit.
  • Page 18 7. The voice of the caller cannot be heard (incoming call). See 3. The base and Can the base and handset handset cannot be be connected? connected. Apply the 1 kHz 77.5 mV sine Check the base TEL-line waveform TEL-line of the circuit and RELAY control circuit.

  • Page 19: Ic And Transistor Voltage Chart

    IC AND TRANSISTOR VOLTAGE CHART Base Unit Unit [V] Unit [V] Ref.No. STBY TALK Note Ref.No. STBY TALK Note ← 1.0-1.1* ← ← ← ← ← ← ← ← 1.6-3.9* 1.5-3.8* Sin Wave 2.0-3.3* 1.9-3.2* Sin Wave 0.2-2.5* 0.2-2.5* Sin Wave 1.5-2.6* 1.4-2.5* Sin Wave...
  • Page 20 Unit [V] Unit [V] Ref.No. STBY TALK Note Ref.No. STBY TALK Note ← ← ← ← ← ← 0.6-1.3 ← ← ← 0-3.3* 0-3.2* ← 0-3.3* ← 0-3.3* 0-3.3* Pulse 0-3.3* 0-3.3* ← 0-3.3* 0-3.3* ← ← ← ← ← Pulse ←...
  • Page 21 Handset Unit Unit [V] Unit [V] Ref.No. STBY TALK Note Ref.No. STBY TALK Note ← ← ← 0.6-1.3* ← ← ← IC601 2.0* ← 2.5* ← ← ← ±0.2 ← ±0.2 ← ← ← ← ← ← ← 1.4-3.7* 1.4-3.7 Sin Wave 1.5-3.0* 1.5-3.0...
  • Page 22 Unit [V] Unit [V] Ref.No. STBY TALK Note Ref.No. STBY TALK Note ← Q601 0.8* 2.5* ← Q602 2.5* ← 0.7* ← ← IC602 Q603 2.5* ← 0.7* 0.0-3.6* 0.0-3.6 Pulse 3.7* Q606 1.2* ← ← 0.0-1.2* Q607 ← ← 0.0-3.0* 0.0-3.0 Pulse...

  • Page 23: Semiconductor Lead Identification

    SEMICONDUCTOR LEAD IDENTIFICATION Base Unit D4/D9/D10/D12/D14: 1N4148 D8: LTL-16KGE D15: HZ11A D3: HZ33-2 D13: HZ5B2 D11: HZ7A1 Anode Cathode Cathode Anode Q1: 2SC4095 Q7: 2SD471 Q11/Q15: 2SC2120 Q13: 2SA812(M) Q10/Q14/Q16: 2SC1623 Q3: 2SC2712 Q4: 2SC2714 Q2/Q6/Q12: 2SC5065 B: Base E: Emitter C: Collector IC1: TB31261AF IC2: MB89176PF...
  • Page 24 Handset Unit D604: SML-310MT D605: RB420D D606/607D610: RLS4148 D608/D609: HZK6C Cathode Cathode Anode Cathode Anode Cathode Anode Anode (Open) Q611/Q612: 2SA812(M) Q601: 2SC4095 Q609/Q610/Q613/Q614: 2SC1623 Q603: 2SC2714 Q602/Q606/Q607: 2SC5065 B: Base E: Emitter C: Collector IC601: TB31261AF IC602: MB89177LPF 39 38 37 36 35 34 33 32 31 30 29 28 27 IF1-IN D-COMP-IN IF1-REF...

  • Page 25: Electrical Parts Location

    ELECTRICAL PARTS LOCATION Base, Main Top View — 26 —...
  • Page 26 Bottom View — 27 —...
  • Page 27 Handset, Main Top View — 28 —...
  • Page 28 Bottom View — 29 —...

  • Page 29: Wiring Diagrams

    WIRING DIAGRAMS Base Unit — 30 —...
  • Page 30 Handset — 31 —...

  • Page 31: Exploded View And Mechanical Parts List

    EXPLODED VIEW AND MECHANICAL PARTS LIST Base Unit RF MODULE (BASE) ANTENNA — 32 —...
  • Page 32 Base Unit LOC. PART NO. REF NO. DESCRIPTION RC009206 GNBZ443013Z BUTTON, PUSH RC009764 GCAS263720Z CASE, BOTTOM RC009203 GCAS347424Z CASE, TOP RC009207 HTML442794Z CHARGE TERMINAL C5210(PBSP) RC002384 LFUT428079Z FOOT RC009205 GCAS456869A HOOK RC009204 GCAS442792A LED LENS PMMA RC000941 SSCW802608N SCREW, P TIGHT BIND HD + D2.6X8 NI RC004893 SSCW802612N...
  • Page 33 Handset MODULE (HANDSET) — 34 —...
  • Page 34 Handset LOC. PART NO. REF NO. DESCRIPTION RC009222 RBLD459840Z BLIND RC009767 GNBZ463721Z BUTTON, FUNCTION RC009213 GCAS347434A CASE, FRONT RC009212 GCAS343014A CASE, REAR RC009218 HTML459366A CHARGE TERMINAL C2680(BSP) RC009765 GCAS462433Z COVER (COMP) ELASTOMER RC009215 GCAS448474Z COVER, BATTERY RC009337 RCUN447997Z CUSHION MOLTOPRENE RC004286 RCUN451209Z CUSHION...

  • Page 35: Parts List

    PARTS LIST PRODUCT SAFETY NOTE: Products marked with a have special characteristics important to safety. Before replacing any of these components, read carefully the product safety notice of this service manual. Don’ t degrade the safety of the product through important servicing. Symbol Symbol ±1...
  • Page 36 LOC. PART NO. REF NO. DESCRIPTION RC005218 BCMM814091Z CERAMIC M/L 4PF 50V C CH RC005218 BCMM814091Z CERAMIC M/L 4PF 50V C CH RC005222 BCMS811091Z CERAMIC M/L 1PF 50V C CK RC005207 BCML813325Z CERAMIC M/L 0.0033UF 50V K B RC005208 BCML814725Z CERAMIC M/L 0.0047UF 50V K B RC004412...
  • Page 37 LOC. PART NO. REF NO. DESCRIPTION C108 RC005204 BCML811025Z CERAMIC M/L 0.001UF 50V K B C109 RC005202 BCML311045Z CERAMIC M/L 0.1UF 16V K B C111 RC000744 BCKB811025Z CERAMIC 0.001UF 50V K YB(B) C112 RC005205 BCML811035Z CERAMIC M/L 0.01UF 50V K B C113 RC005204 BCML811025Z...
  • Page 38 LOC. PART NO. REF NO. DESCRIPTION C161 RC005216 BCMM813304Z CERAMIC M/L 33PF 50V J CH C162 RC005216 BCMM813304Z CERAMIC M/L 33PF 50V J CH C163 RC005216 BCMM813304Z CERAMIC M/L 33PF 50V J CH C164 RC005216 BCMM813304Z CERAMIC M/L 33PF 50V J CH C168 RC005216 BCMM813304Z...
  • Page 39 LOC. PART NO. REF NO. DESCRIPTION C640 RC005207 BCML813325Z CERAMIC M/L 0.0033UF 50V K B C641 RC008757 BCMM818204Z CERAMIC M/L 82PF 50V J CH C642 RC008731 BCXK311050Z CERAMIC M/L (2125) 1UF 16V Z F C643 RC005205 BCML811035Z CERAMIC M/L 0.01UF 50V K B C644 RC008294 BCSH116896Z...
  • Page 40 LOC. PART NO. REF NO. DESCRIPTION C713 RC005205 BCML811035Z CERAMIC M/L 0.01UF 50V K B C714 RC005205 BCML811035Z CERAMIC M/L 0.01UF 50V K B C715 RC005218 BCMM814091Z CERAMIC M/L 4PF 50V C CH C716 RC005216 BCMM813304Z CERAMIC M/L 33PF 50V J CH C717 RC005204 BCML811025Z...
  • Page 41 LOC. PART NO. REF NO. DESCRIPTION FILTERS RC008652 BFLY0967001 CERAMIC FL-967 FFE1054MS11SBL RC008652 BFLY0967001 CERAMIC FL-967 FFE1054MS11SBL RC008299 BFLY0955001 FL-955 NSVA528 FT601 RC008299 BFLY0955001 FL-955 NSVA528 FT602 RC008652 BFLY0967001 CERAMIC FL-967 FFE1054MS11SBL FT603 RC008652 BFLY0967001 CERAMIC FL-967 FFE1054MS11SBL IC'S RC009741 BDEY4060003 TB31261AF(ER) RC009739...
  • Page 42 LOC. PART NO. REF NO. DESCRIPTION L621 RC009749 BLZY0218476 INDUCTOR MOLDED CHIP LZ-218 CIH10T4N7S T 4.7NH RC003234 BTFY0265001 TRANSFORMER HYBRID TF-265 AT-24E7-1B(295403) TRANSISTORS RC004867 BDBC4095672 DB-810 2SC4095-R47 T1 RC008760 BDBC5065124 DB-848 2SC5065-Y(TE85R) RC001637 BDBC2712303 DB-381 2SC2712-GR TE85L RC002245 BDBC2714124 DB-718 2SC2714-Y TE85L RC008760 BDBC5065124 DB-848 2SC5065-Y(TE85R)
  • Page 43 LOC. PART NO. REF NO. DESCRIPTION RC005255 BRFC164714Z CARBON FIXED CHIP 470 1/16W J RC008091 BRFC165614Z CARBON FIXED CHIP 560 1/16W J RC005261 BRFC168224Z CARBON FIXED CHIP 8.2K 1/16W J RC005280 BRFC161534Z CARBON FIXED CHIP 15K 1/16W J RC005260 BRFC166834Z CARBON FIXED CHIP 68K 1/16W J RC005282...
  • Page 44 LOC. PART NO. REF NO. DESCRIPTION RC005257 BRFC164734Z CARBON FIXED CHIP 47K 1/16W J RC005240 BRFC161024Z CARBON FIXED CHIP 1K 1/16W J RC005278 BRFC161244Z CARBON FIXED CHIP 120K 1/16W J RC005281 BRFC162224Z CARBON FIXED CHIP 2.2K 1/16W J RC005260 BRFC166834Z CARBON FIXED CHIP 68K 1/16W J RC008479...
  • Page 45 LOC. PART NO. REF NO. DESCRIPTION R125 RC002899 BRFC180004Z CARBON FIXED CHIP 0 1/8W J R126 RC005311 BRFC160004Z CARBON FIXED CHIP 0 1/16W J R128 RC002899 BRFC180004Z CARBON FIXED CHIP 0 1/8W J R129 RC002898 BRFC010004Z CARBON FIXED CHIP 0 1/10W J R601 RC005262 BRFC168234Z...
  • Page 46 LOC. PART NO. REF NO. DESCRIPTION R645 RC009626 BRFC161804Z CARBON FIXED CHIP 18 1/16W J R646 RC005282 BRFC162714Z CARBON FIXED CHIP 270 1/16W J R650 RC008765 BRFC161004Z CARBON FIXED CHIP 10 1/16W J R651 RC005245 BRFC161834Z CARBON FIXED CHIP 18K 1/16W J R652 RC008765 BRFC161004Z...
  • Page 47 LOC. PART NO. REF NO. DESCRIPTION R701 RC005243 BRFC161054Z CARBON FIXED CHIP 1M 1/16W J R702 RC005243 BRFC161054Z CARBON FIXED CHIP 1M 1/16W J R703 RC005311 BRFC160004Z CARBON FIXED CHIP 0 1/16W J R704 RC005240 BRFC161024Z CARBON FIXED CHIP 1K 1/16W J R705 RC005311 BRFC160004Z...

  • Page 48: Assembly Parts List

    WSLV466026Z SLEEVE RC009826 WSLV494239Z SLEEVE ASSEMBLY PARTS LIST NOTE: Following part numbers are not available as replacement parts. Order parts necessary for repair or contact the Toshiba Factory Service Center. LOC. PART NO. REF NO. DESCRIPTION RC009731 AC303BHBA BASE MAIN PCB ASSEMBLY...

  • Page 49: Specifications

    SPECIFICATIONS MEASUREMENT CONDITIONS 1. Standard Voltage: DC 3.8 V ±0.025 V Handset Unit AC 120 V ±3 V 60 Hz Base Unit 25 °C ±5 °C 2. Temperature: 3. Channel: Handset (TX Frequency) Base (TX Frequency) 902.144772 MHz 924.715792 MHz 902.244204 MHz 924.815224 MHz 902.343636 MHz...
  • Page 50 BASE UNIT RECEIVER Unit Nominal Limit −113 < −100 1. Sensitivity 12dB SINAD at 30 kHz Dev. (with CCITT Filter) 2. Frequency Response (Ref: 1 kHz) 0.3 kHz +15.0 +11.0 ~ +19.0 −22.0 −26.0 ~ −18.0 3.0 kHz 3. Distortion at 1 mV RF Input <...
  • Page 51 HANDSET UNIT RECEIVER Unit Nominal Limit −114 1. Sensitivity 12 dB SINAD at 30 kHz Dev. (with CCITT Filter) <−100 2. Frequency Response (Ref: 1 kHz) 0.3 kHz +15.0 +11.0 ~ +19.0 −20.0 −24.0 ~ −16.0 3.0 kHz −15 −20 ~ −10 3.
  • Page 52 TOSHIBA AMERICA CONSUMER PRODUCTS, INC. 82 TOTOWA ROAD, WAYNE, N.J. 07470 TOSHIBA HAWAII, INC. 327 KAMAKEE ST., HONOLULU, H.I. 96814...

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