Toshiba FT-8508 Service Manual
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Toshiba FT-8508 Service Manual

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FILE NO. 2B0-9804
SERVICE MANUAL
CORDLESS TELEPHONE
FT-8508
PUBLISHED IN JAPAN, Jun., 1998

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  • Page 1 FILE NO. 2B0-9804 SERVICE MANUAL CORDLESS TELEPHONE FT-8508 PUBLISHED IN JAPAN, Jun., 1998...

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS ........................1 OPERATING CONTROLS ........................2 ALIGNMENT PROCEDURE ....................... 3 BLOCK DIAGRAMS ........................... 9 SCHEMATIC DIAGRAMS ........................ 14 TROUBLESHOOTING HINTS ......................24 IC AND TRANSISTOR VOLTAGE CHART..................31 SEMICONDUCTOR LEAD IDENTIFICATION .................. 36 ELECTRICAL PARTS LOCATION....................41 WIRING DIAGRAMS ........................

  • Page 3: Operating Controls

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

  • Page 4: Alignment Procedure

    ALIGNMENT PROCEDURE Test Mode For Base Unit Press the “ ” and “#” keys at the same time about 1.5 seconds while turning the power on, the confirmation beep will sound to indicate that the unit is in the test mode. 1.
  • Page 5 Test Mode For Handset Unit To perform the TEST mode, turn the power ON by pressing the “ ” and “#” buttons at the same time. When entered the TEST mode, the bell rings and the unit enters TEST mode 1 . ( Refer to the following table. ) 1.
  • Page 6 Base Unit Transmitter Section Connection BASE RF PCB BASE MAIN PCB AF GEN. Test Point Power Meter Test Point DC IN TEL Line 1kHz 61.0mV 9V Jack Jack Test Point Frequency Counter AC 120V DC 9V Adapter 60Hz Deviation Meter Preset Place the Base Unit in VCO/TX FREQ ADJ mode in accordance with the procedure on page 3.
  • Page 7 Receiver Section Connection BASE RF PCB BASE MAIN PCB AC Voltmeter RF SG Dummy Load (600-ohm) − − TEL Line DC IN Jack Test Point 9V Jack DC Voltmeter AF Terminal AC 120V DC 9V 60Hz Adapter Preset Place the Base Unit in RX SENS mode (step 4) in accordance with the procedure on page 3. Alignment Procedure Step Preset to...
  • Page 8 Handset Unit Transmitter Section Connection HANDSET MAIN PCB HANDSET RF PCB AF GEN. Test Point Power Meter Test Point Battery 1kHz 11.0mV MIC + Pin Terminals Test Point Frequency Counter DC Power Supply Deviation DC 3.8V Meter Preset Place the Handset in VCO/TX FREQ. ADJ mode in accordance with the procedure on page 4. Alignment Procedure Step Adjustment...
  • Page 9 Receiver Section Connection HANDSET RF PCB HANDSET MAIN PCB AC Voltmeter RF SG Dummy Load (150-ohm) J602 − − Battery Connector Test Point Terminals J601 DC Voltmeter DC Power Supply AF Terminal DC 3.8V Preset Place the Handset in RX SENS mode (step 4) in accordance with the procedure on page 4. Alignment Procedure Step Preset to...

  • Page 10: Block Diagrams

    BLOCK DIAGRAMS Handset, Main —9 —...
  • Page 11 Handset, RF —10 —...
  • Page 12 Base, RF —11 —...

  • Page 19: Troubleshooting Hints

    TROUBLESHOOTING HINTS 1. The bell does not ring. When the INTCOM key of See 2. The bell does not the base is pressed, does ring & page does not ring. the ringer on the handset ring? When the TEL SG is joined Check IC3 and TEL network with the base to make bell circuit.
  • Page 20 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 IC603. while in TALK MODE. handset is pressed, can the Can key touch sound be pulse output at pin 38 of...
  • Page 21 3. The base and handset cannot be connected. Check IC18 and its Check whether the base is peripheral circuit. able to set in the test mode 1. Check the TX POWER and Check base RF unit. the TX FREQUENCY on the base unit.
  • Page 22 Set the handset in the test Check whether there is a Check VR601, R619, R632, mode 3, check whether 250Hz data waveform at R634, R635, R636 deviation of the TX data is Pin 9 of J601. and C611. app. 7 kHz Dev. Check handset RF unit.
  • Page 23 4. Will not dial out. (TONE) Check whether there is a DTMF waveform on Pin 11 Check IC10 and IC1. of IC1. Check whether there is a DTMF waveform on Pin 7 Check IC2. of IC2. (PULSE) Check whether there is a Check IC18.
  • Page 24 5. TROUBLE WITH INTERCOM MODE 5-1. The voice from the Base unit cannot be heard on the Handset. Check whether there is an Check MC401 and IC20. audio waveform on Pin 23 of IC20. Check Pin 2 of IC15. 5-2. The voice from the Handset cannot be heard on the Base unit. Check whether there is an Check IC15.
  • Page 25 6. TROUBLE WITH SPEAKERPHONE MODE 6-1. The voice of the caller cannot be heard (INCOMING CALL). Check whether there is an Check IC15. audio waveform on Pin 8 of IC15 (Line 2). Check whether there is an Check IC16, RL1 and Q8. audio waveform on Pin 1 of IC16.

  • Page 26: Ic And Transistor Voltage Chart

    IC AND TRANSISTOR VOLTAGE CHART Transistors Unit [V] Unit [V] Ref. Ref. STBY TALK Note STBY TALK Note Q201 Q202 Q203 Q206 Q207 Q212 Q501 Q502 Q503 Q506 Q507 Q511 Q512 Q601 —31—...
  • Page 27 Unit [V] IC’S Unit [V] Ref. Ref. STBY TALK Note STBY TALK Note Q602 Q603 Q604 Q605 Q606 Q608 Q609 Q610 Q611 IC10 —32—...
  • Page 28 Unit [V] Unit [V] Ref. Ref. STBY TALK Note STBY TALK Note IC10 IC13 IC14 IC15 IC18 IC16 IC18 IC19 —33—...
  • Page 29 Unit [V] Unit [V] Ref. Ref. STBY TALK Note STBY TALK Note IC19 IC202 IC20 IC21 IC501 IC22 IC201 IC502 IC202 —34—...
  • Page 30 Unit [V] Unit [V] Ref. Ref. STBY TALK Note STBY TALK Note IC502 IC603 IC601 IC602 IC604 IC605 IC603 —35—...

  • Page 31: Semiconductor Lead Identification

    SEMICONDUCTOR LEAD IDENTIFICATION Base Unit D23: HSM88WA D201: 1SS226 D1: HZ33-2 D401: VR1102W D2/D6/D14 D402/D403/D405: PG1102W D25/D26/D27: 1N4148 D15: 1N4003 D22: HZ7A1 Anode Anode/Cathode Cathode Anode Cathode Anode Cathode Cathode Anode Cathode D9:RLS4148 D406: BRPG1202W D24: HZK6C D202/D203: 1SV270 Anode Anode Cathode Anode...
  • Page 32 IC1/IC15 IC2/IC16 TC4066BF M5223L LTV-817 IN/OUT1 OUT/IN1 CONT1 OUT/IN2 CONT4 IN/OUT2 IN/OUT4 OUT/IN4 CONT2 CONT3 OUT/IN3 IN/OUT3 I C 1 3 I C 1 0 T K 1 1 2 3 2 A M T C 3 5 2 1 9 F IR3N74AN T O N E C O N T...
  • Page 33 IC20 IC201 MC33219AP MC3361CDR2 Mixer Input Crystal Osc. Mixer Audio Output Mute Scan Control Squelch Limiter Input Input MUTE Filter Output Decoupling Filter Input Quad Demodulator Audio Input IC202 M64084AGP MIX REF Tx OUT MIX IN Tx Vcc Rx Vcc Tx GND Rx GND Xout...
  • Page 34 Handset D605: S1ZB20 D608: LTL-16KPE D601/D604: RLS4148 − Cathode Anode Cathode Anotde D607: HZK6C D606: HSM88WA D501: 1SS226 D502/D503: 1SV270 Anode Anode/Cathode Cathode Cathode Anode Cathode Q503: 2SC2714 Q501: 2SC4095 Q506/Q507/Q512: 2SC5065 Q601/Q602/Q603/Q604 /Q608/Q610/Q611: 2SC2712 Q502/Q511/Q605 /Q606/Q609: 2SA1162 B: Base E: Emitter C: Collector IC502...
  • Page 35 IC601 IC602 IR3N74AN TK11232AM CONT MUTE MUTE EREC CREC NOISE BYPASS Vout VREF IC603 IC605 MB89174APF RH5VL28CA IC604 RH5VL33CA DTMF P36/INT2 P37/BZ P00/L10 MDD0 P01/L11 MDD1 P02/L12 P03/L13 P04/L14 P05/L15 P50/(X0A) P06/L16 P51(Z1A) P07/L17 — 40 —...

  • Page 36: Electrical Parts Location

    ELECTRICAL PARTS LOCATION Base, Main — 41—...
  • Page 37 Base, RF — 42 —...
  • Page 38 Base, Key — 43 —...
  • Page 39 Handset, Main — 44 —...
  • Page 40 Handset, RF — 45 —...

  • Page 41: Wiring Diagrams

    WIRING DIAGRAMS Base — 46 —...
  • Page 42 Handset IC603 J601 PORTABLE RF B501 PE1294DA [TOP VIEW] SOLDERING W501 W-072147 J502 JK-736[9P] — 47 —...

  • Page 43: Exploded View And Mechanical Parts List

    EXPLODED VIEW AND MECHANICAL PARTS LIST Base, Unit Note: To remove the RF Assembly from the unit, remove four screws 24 . Three screws 23 are used for fastening the Shield Cases 26 and 27 . — 48 —...
  • Page 44 Base Unit LOC. PART NO. REF. NO. DESCRIPTION RC008819 GNBZ358191Z Button, Function RC005680 GCAS257882Z Case, Battery RC008817 GCAS258187Z Case, Bottom RC008816 GCAS258185Z Case, Top RC005686 HTML457884Z Charge Terminal C5191(PBP) RC004860 HTML451849Z Contact Plate C5191(PBP) RC002384 LFUT428079Z Foot BUMPON SJ-5916 1.6T RC005689 LHDZ453179Z Holder, Mic...
  • Page 45 Handset Note: To remove the RF Assembly from the unit, remove four screws 69 . Three screws 68 are used for fastening the Shield Cases 70 and 71 . — 50 —...
  • Page 46 Handset LOC. PART NO. REF. NO. DESCRIPTION RC008714 RBLD457881Z Blind RC008826 GNBZ458195Z Button, Function RC008706 GNBZ457891Z Button, Push RC008825 GCAS358194Z Case, Front RC008701 GCAS157888Z Case, Rear RC008707 HTML457893Z Charge Terminal C2680(BSP) RC008703 GCAS457897Z Cover ELASTOMER RC008702 GCAS357889Z Cover, Battery RC008715 RCUM417955Z Cushion MOLTPLENE...

  • Page 47: 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 ±...
  • Page 48 LOC. PART NO. DESCRIPTION RC001632 BCXT813335Z CERAMIC 0.033UF 50V K B RC001068 BCXT811025Z CERAMIC 0.001UF 50V K B RC003977 BCBH811514Z CERAMIC 150PF 50V J CH RC001069 BCXT811035Z CERAMIC 0.01UF 50V K B RC001070 BCXT811525Z CERAMIC 0.0015UF 50V K B RC001068 BCXT811025Z CERAMIC 0.001UF 50V K B...
  • Page 49 LOC. PART NO. DESCRIPTION C129 RC001807 BCAZ812296Z ELECTROLYTIC 2.2UF 50V M C-156 C130 RC001794 BCAZ111016Z ELECTROLYTIC 100UF 10V M C-156 C131 RC008731 BCXK311050Z CERAMIC 1UF 16V Z F C132 RC001069 BCXT811035Z CERAMIC 0.01UF 50V K B C133 RC001794 BCAZ111016Z ELECTROLYTIC 100UF 10V M C-156 C134 RC004145...
  • Page 50 LOC. PART NO. DESCRIPTION C227 RC005202 BCML311045Z CERAMIC 0.1UF 16V K B C228 RC005214 BCMM812214Z CERAMIC 220PF 50V J CH C229 RC005225 BCSS114796Z TANTALUM CHIP 4.7UF 10V M A C-241 C230 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C231 RC005214 BCMM812214Z CERAMIC 220PF 50V J CH C232...
  • Page 51 LOC. PART NO. DESCRIPTION C275 RC005360 BCMM816092Z CERAMIC 6PF 50V D CH C276 RC005218 BCMM814091Z CERAMIC 4PF 50V C CH C278 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C279 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C280 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C281 RC005216...
  • Page 52 LOC. PART NO. DESCRIPTION C533 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C534 RC008785 BCMM814098Z CERAMIC 4PF 50V B CH C535 RC008755 BCMM815098Z CERAMIC 5PF 50V B CH C536 RC005207 BCML813325Z CERAMIC 0.0033UF 50V K B C537 RC005208 BCML814725Z CERAMIC 0.0047UF 50V K B C538 RC005206...
  • Page 53 LOC. PART NO. DESCRIPTION C581 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C582 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C583 RC005216 BCMM813304Z CERAMIC 33PF 50V J CH C585 RC004410 BCBH814091Z CERAMIC 50V C CH C586 RC005205 BCML811035Z CERAMIC 0.01UF 50V K B C590 RC005205 BCML811035Z CERAMIC...
  • Page 54 LOC. PART NO. DESCRIPTION C643 RC002229 BCXT511045Z CERAMIC 0.1UF 25V K B C644 RC008843 BCML313335Z CERAMIC 0.033UF 16V K B C645 RC002229 BCXT511045Z CERAMIC 0.1UF 25V K B CT201 RC005226 BCTY0096100 TRIMMER CT-096 CTZ3S10A-W1PF55 CT501 RC005226 BCTY0096100 TRIMMER CT-096 CTZ3S10A-W1PF55 DIODES RC002468 BDAY0492008...
  • Page 55 LOC. PART NO. DESCRIPTION IC’s RC005471 BDEY1180003 TC4066BF(EL) RC001086 BDEY0582001 M5223L RC001640 BDEY1146001 PC817CD RC002588 BDEY2207001 IR3N74AN IC10 RC005107 BDEY2485003 TC35219F (TP1) IC13 RC005648 BDEY3414003 TK11232AM TAPE IC14 RC004906 BDEY2936003 RH5VL33CA-T1 IC15 RC005471 BDEY1180003 TC4066BF(EL) IC16 RC001086 BDEY0582001 M5223L IC018 RC008811 BDDY0739002 UC2198A...
  • Page 56 LOC. PART NO. DESCRIPTION L203 RC005237 BLZY0127826 INDUCTOR LZ-127 0.0082UH TAPE L204 RC004790 BLZY0117339 INDUCTOR LZ-117 3.3UH K TAPE L205 RC004877 BLZY0087120 INDUCTOR LZ-087 12UH J TAPE L206 RC008786 BLZY0127127 INDUCTOR LZ-127 0.012UH J TAPE L207 RC005236 BLZY0127686 INDUCTOR LZ-127 0.0068UH TAPE L208 RC004882 BLZY0108826...
  • Page 57 LOC. PART NO. DESCRIPTION RESISTORS RC002323 BRFC014744Z CARBON 470K 1/10W J TAPING RC002306 BRFC012224Z CARBON 2.2K 1/10W J TAPING RC002307 BRFC012234Z CARBON 22K 1/10W J TAPING RC002298 BRFC011044Z CARBON 100K 1/10W J TAPING RC002321 BRFC014724Z CARBON 4.7K 1/10W J TAPING RC002321 BRFC014724Z CARBON...
  • Page 58 LOC. PART NO. DESCRIPTION RC002618 BRFC011244Z CARBON 120K 1/10W J TAPING RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING RC002311 BRFC012734Z CARBON 27K 1/10W J TAPING RC002298 BRFC011044Z CARBON 100K 1/10W J TAPING...
  • Page 59 LOC. PART NO. DESCRIPTION R103 RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING R104 RC002322 BRFC014734Z CARBON 47K 1/10W J TAPING R106 RC002329 BRFC016824Z CARBON 6.8K 1/10W J TAPING R107 RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING R108 RC002306 BRFC012224Z CARBON 2.2K 1/10W J TAPING R109 RC002321...
  • Page 60 LOC. PART NO. DESCRIPTION R170 RC002297 BRFC011034Z CARBON 10K 1/10W J TAPING R171 RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING R172 RC002322 BRFC014734Z CARBON 47K 1/10W J TAPING R176 RC002298 BRFC011044Z CARBON 100K 1/10W J TAPING R177 RC002296 BRFC011024Z CARBON 1K 1/10W J TAPING R178 RC002296...
  • Page 61 LOC. PART NO. DESCRIPTION R226 RC005241 BRFC161034Z CARBON 10K 1/16W J TAPING R227 RC005240 BRFC161024Z CARBON 1K 1/16W J TAPING R228 RC005256 BRFC164724Z CARBON 4.7K 1/16W J TAPING R229 RC005434 BRFC163914Z CARBON 390 1/16W J TAPING R230 RC008765 BRFC161004Z CARBON 10 1/16W J TAPING R231 RC005250...
  • Page 62 LOC. PART NO. DESCRIPTION R523 RC005242 BRFC161044Z CARBON 100K 1/16W J TAPING R524 RC005261 BRFC168224Z CARBON 8.2K 1/16W J TAPING R526 RC005241 BRFC161034Z CARBON 10K 1/16W J TAPING R527 RC005240 BRFC161024Z CARBON 1K 1/16W J TAPING R528 RC005256 BRFC164724Z CARBON 4.7K 1/16W J TAPING R529 RC005434...
  • Page 63 LOC. PART NO. DESCRIPTION R622 RC005279 BRFC161514Z CARBON 150 1/16W J TAPING R623 RC005432 BRFC161544Z CARBON 150K 1/16W J TAPING R624 RC005242 BRFC161044Z CARBON 100K 1/16W J TAPING R625 RC005242 BRFC161044Z CARBON 100K 1/16W J TAPING R626 RC005240 BRFC161024Z CARBON 1K 1/16W J TAPING R627 RC005281...
  • Page 64 LOC. PART NO. DESCRIPTION SWITCHS RC003604 BSWY0755001 SW-755 SBHA12B-06 RC005118 BSWY0756001 SLIDE SW-756 SBHA13B-06 CRYSTALS RC005108 BFKY0025001 RESONATOR FK-025 480KHZ RC003720 BQXY0526001 CRYSTAL QX-526 4.192M X202 RC004888 BQXY0627001 CRYSTAL QX-627 13.865MHZ X502 RC004888 BQXY0627001 CRYSTAL QX-627 13.865MHZ X601 RC003629 BQXY0542001 CRYSTAL QX-542 3.579545MHZ OTHER ELECTRICAL PARTS...
  • Page 65 LOC. PART NO. DESCRIPTION RC008795 UCZZ69400BZ QUICK REFERENCE GUIDE RC005301 UDZZ44824ZZ REGISTRATION CARD RC006829 WCTZ458209Z SHIPPING CARTON BOX RC005080 WSLV453148Z SLEEVE RC008723 WSLV456258Z SLEEVE RC008719 VNYH1103000 VINYL BAG 100X300X0.05T HIPE RC005067 VNYH1255000 VINYL BAG 250X500X0.05T HIPE RC008720 VNYL2304070 VINYL BAG 300X400X700X0.07T RC002946 VNYL3070800...

  • Page 66: Assembly Parts List

    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. DESCRIPTION RC008873 AC400BLBA BASE MAIN ASSEMBLY RC008746 AC400BLBB BASE RF ASSEMBLY RC008874...

  • Page 67: Specifications

    SPECIFICATIONS Measurement Conditions Standard Voltage: Handset Unit DC 3.6 V ±0.025 V Base Unit AC 120 V ±3 V 60 Hz Temperature: 25 °C ±5 °C Channel: Handset (TX Frequency) Base (TX Frequency) 902.080435MHz 925.989636MHz 902.130671MHz 926.039871MHz 902.180906MHz 926.090107MHz 902.231142MHz 926.140342MHz 902.281377MHz 926.190577MHz...
  • Page 68 Base Unit Receiver Unit Nominal Limit −115 < −107 Sensitivity 12dB SINAD (CCITT Filter ON) −0.5 −4.5 ~ +3.5 Frequency Response 0.3 kHz − 6 −10 ~ − 2 3.0 kHz Distortion at 1 mV RF Input < 5 S/N ratio at 1 mV RF Input (CCITT Filter ON, Compander ON) >...
  • Page 69 DTMF Output (600 Ω load) −7 > −10 a. Minimum Level On Single Tone Low Group −5 > −8 High Group −3 b. DTMF Level < 0 c. DTMF Frequency Row 1 687 ~ 707 Row 2 759 ~ 781 Row 3 840 ~ 864 Row 4...

  • Page 70: Power Consumption

    Transmitter RF Power (50 Ω Load) −7 −10 ~ −4 Modulation Sensitivity 7 ~ 18 −1 −5 ~ +3 Frequency Response 0.3 kHz −1 −5 ~ +3 3.0 kHz Frequency Tolerance (25 °C) ±1500 Code Deviation < 11 Distortion < 5 S/N Ratio (CCITT Filter ON, Compander ON) >...
  • Page 71 MECHANICAL PARTS LIST...

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