Technics SA-EH770 Service Manual
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Technics SA-EH770 Service Manual

Technics SA-EH770 Service Manual

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AD0104055C3
Tuner/Amplifier
SA-EH770
Colour
(S)...................Silver Type
Areas
(GC).................Asia, Latin America, Middle Near East and Africa.
(GN).................Oceania.
SPECIFICATIONS
1

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Summary of Contents for Technics SA-EH770

  • Page 1 AD0104055C3 Tuner/Amplifier SA-EH770 Colour (S)....Silver Type Areas (GC)....Asia, Latin America, Middle Near East and Africa. (GN)....Oceania. SPECIFICATIONS...

  • Page 2: Before Repairs

    1. Before Repairs 1. Turn off the power supply. Using a 10 , 10 W resistor, connect both ends of power supply capacitors (C701, C703 and C702, C704) in order to discharge the voltage.

  • Page 3: Protection Circuitry

    2. Before turning the power supply on, after completion of repair, slowly apply the primary voltage by using a power supply voltage controller to make sure that the consumed current at 50 Hz in NO SIGNAL mode should be shown below with respectto supply voltage 110/240 V.
  • Page 4 AC power supply cord for (GN) area (RJA0035-X)........1 pc. AM loop antenna set (RSA0022-L)........1 pc. FM indoor antenna (RSA0006-J)........1 pc.
  • Page 5 Speaker cords (REE0853)........2 pcs. (REE1057)........2 pcs. Remote control transmitter (EUR7702060)......1 pc. Remote control batteries (R6/LR6, “AA”, UM-3)....2 pcs. Note: These are available on sales route.

  • Page 6: Location Of Controls

    Power plug adaptor for (GC) area only (SJP5213-2)........1 pc. 4. Location of Controls 5. Operation Checks and Component Replacement Procedures Note: The contents of this section describes for Europe. So please use this section as a reference. This section describes procedures for checking the operation of the major printed circuit boards and replacing the main components.

  • Page 7: Checking For The Ac In P.c.b

    For reassembly after operation checks or replacement, reverse the respective procedures. Special reassembly procedures are described only when required. 5.1. Checking for the AC IN P.C.B. Check the AC IN P.C.B. as shown below.

  • Page 8: Checking For The Operation P.c.b

    5.2. Checking for the operation P.C.B. Follow the (Step 1) - (Step 3) of item 5.1.
  • Page 10 Check the operation P.C.B. as shown below.

  • Page 11: Checking For The Main P.c.b

    5.3. Checking for the main P.C.B. Follow the (Step 1) - (Step 3) of item 5.1. Follow the (Step 1) - (Step 6) of item 5.2.
  • Page 17 Check the main P.C.B. as shown below.

  • Page 18: Replacement For The Regulator Transistor

    5.4. Replacement for the regulator transistor Follow the (Step 1) - (Step 3) of item 5.1.

  • Page 20: Replacement For The Power Ic

    5.5. Replacement for the power IC Follow the (Step 1) - (Step 3) of item 5.1. Follow the (Step 1) - (Step 6) of item 5.2. Follow the (Step 1) - (Step 10) of item 5.3.

  • Page 21: To Supply Power Source

    6. To Supply Power Source This unit SA-EH770 is designed to operate on power supplied form system connected. For system connection, refer to Fig. 6-1. Fig. 6-1.
  • Page 22 When the unit SA-EH770 has to test and service alone, use the following method to supply power source. 1. Short the section between W902A Pin 3 and C740 (-) (GND). (Refer to Fig. 6-2. 2. Connect this unit to an AC power supply cord.

  • Page 23: Self-Diagnostic Function

    Notes: Use only this method when checking the voltage etc.. In case of checking the operations, use the system connections to supply power source. 7. Self-Diagnostic Function This unit is equipped with a self-diagnostic function which, in the event of a malfunction, automatically displays a code indicating the nature of the malfunction.
  • Page 24 7.2. To return to the normal display 1. For U70 CD/U70 DECK...

  • Page 25: Display Contents

    - Press an any operation button on the tuner/amplifier. - To re-display the code, switch the power off (POWER STANDBY button), and then switch power back on again. 2. For F61 - If F61 is displayed, the power will automatically be switched off and the standby indicator will light up.
  • Page 26 Fig. 7-3. 2. Breakage of flat cables. (Check and replace.) 3. If the problem is not corrected by items 1 and 2 above, this indicates a faulty IC. SA-EH770: IC901 (C2BBFD000297) SL-EH770: IC451 (C2BBFD000256) RS-DV250: IC701 (M38503M2406F) Check these ICs and replace.

  • Page 27: Schematic Diagram Notes

    When the power switch is switched on, it automatically switches back off, making it impossible to switch power on. Correction procedure Faulty Tuner/Amplifier (SA-EH770) output IC (IC601). (When a DC voltage is applied to speaker terminals.) 8. Schematic Diagram Notes This schematic diagram may be modified at any time with the development of new technology.
  • Page 28 S905: FM mode switch (FM AUTO/MONO) S906: Tuning mode switch (TUNING MODE) S907: Set switch (SET) S908: Source input switch (INPUT SELECTOR) S909: 6 ch discrete input switch (6 CH DISCRETE INIPUT) S910: Tuning down switch (TUNING, S911: Tuning up switch (TUNING, S912: Tuner/band switch (TUNER/BAND) S913:...
  • Page 29 VR901: Volume control VR (VOLUME) Indicated voltage values are the standard values for the unit measured by the DC electronic circuit tester (high-impedance) with the chassis taken as standard. Therefore, there may exist some errors in the voltage values, depending on theinternal impedance of the DC circuit tester.
  • Page 30 : AM signal line : AM OSC signal line : FM signal line : FM OSC signal line : Audio signal line...
  • Page 31 : Mic signal line 9. Schematic Diagram 10. Printed Circuit Board Diagram 11. Type Illustration of ICs, Transistors and Diodes 12. Wiring Connection Diagram 13. Block Diagram 14. Terminal Function of ICs 14.1. IC901 (C2BBFD000297): System Control/FL Drive...
  • Page 32 Terminal Function Name CHECK Clock check signal input 2 LC72 DO O PLL data signal output for tuner unit (Z120) 3 LC72 CE O Chip enable signal output for tuner unit (Z120) 4 LC72 DI/ IF count data/stereo detect signal input from tuner unit (Z120) 5 LC72 CK O Clock signal output for tuner...
  • Page 33 Terminal Function Name RDS data signal input DATA (Not used, connected to GND) Remote control signal input REMO Grid signal output Segment signal output Power supply terminal V DD 3 Segment signal output Power supply terminal (Negative) Segment signal output Power supply terminal V DD 4 Segment signal output...

  • Page 34: Replacement Parts List

    Terminal Function Name MUTE O Muting signal output Not used, open 88 POWER O Power control signal output GND terminal V SS 2 Power supply terminal V DD 2 91 MUTE2 O Muting signal output Not used, open 93 MUTE3 O Muting signal output SH CS O Chip select signal output for...
  • Page 35 GASKET RGW0317-S KNOB,VOLUME RHN90001 RKA0106-N FOOT RING RKF0606L-K1 BACK GRILL RKW0581-1V FL WINDOW RMN0427A CABLE HOLDER RYP1005A-S FRONT PANEL ASS'Y 12-1 RGB0025-A TECHNICS BADGE SHG1654 RUBBER XTB3+10JFZ SCREW XTB3+8JFZ SCREW XTW3+15T SCREW XTBS3+8JFZ1 SCREW RGW0178-1S KNOB,MIC VOL. RMN0582 HOLDER XTB3+12FFZ...
  • Page 36 Ref. No. Part No. Part Name & Description Remarks SJP5213-2 PLUG ADAPTOR K2DR42E00003 (GC) RJA0019-1X AC POWER SUPPLY (GC) CORD RJA0035-X AC POWER SUPPLY (GN) CORD RQCA0801 DEMO GUIDE RQCB0169 SERVICE CENTER LIST RQT5753-B OPERATING <IA> INSTRUCTIONS RQT5754-G OPERATING (GC)<IB> INSTRUCTIONS RSA0006-J FM INDOOR ANTENNA...
  • Page 37 C616 ECEA1HKNR47B 50V 0.47U Ref. No. Part No. Part Name & Description Remarks C617,18 ECKR2H103ZU 500V 0.01U C619-21 ECBT1H104KB5 50V 0.1U C622 RCE1AKA101BG 10V 100U F2A1A1010020 C624-31 ECBT1H104KB5 50V 0.1U C632 ECBT1H473KB5 50V 0.047U C633,34 ECBT1H104KB5 50V 0.1U C635-37 ECBT1H473KB5 50V 0.047U C639-44 ECBT1H102KB5...
  • Page 38 Ref. No. Part No. Part Name & Description Remarks C762 ECA1CAK220XB 16V 22U (GC) C791 ECKWRS102MBC 1000U C901 EEAFC0J101B 6.3V 100U C902 RCE1AM102BV 10V 1000U C903,04 ECBT1H103KB5 50V 0.01U C905 ECBT1H102KB5 50V 1000P F1D1H102A012 C907,08 ECBT1H471KB5 50V 470P F1D1H471A012 C909 ECBT1H102KB5 50V 1000P F1D1H102A012...
  • Page 39 Ref. No. Part No. Part Name & Description Remarks D611 MA4051M DIODE MAZ40510M D657-59 MA165 DIODE MA2C165 D701-04 1N5402BF DIODE D705 RL1N4003N02 DIODE D711 RL1N4003N02 DIODE D717-20 RL1N4003N02 DIODE D721 MA4300M DIODE MAZ43000M D723 MA4150M DIODE MAZ41500M D725 MA4082LTA DIODE MAZ40820LF D730 MA4091H...
  • Page 40 FL901 A2BB00000084 Ref. No. Part No. Part Name & Description Remarks IC201 BU4053BCFE2 IC401 TA2011S C1BA00000152 IC601 RSN311W64B IC901 C2BBFD000297 JK551 SJT3213 CONNECTOR FAN MOTOR K1KA02A00008 (GC) JK601,02 K4BC04B00028 JACK JK603 K2HA103B0015 JACK JK701 SJS9236-1 JACK,AC INLET K2AA2B000002 JK901,02 RJJ65MA01 JACK,MIC K2HB102J0032 JK903...
  • Page 41 Ref. No. Part No. Part Name & Description Remarks Q556 2SC5398RSTA TRANSISTOR B1AACF000059 (GC) Q557 2SA1995RSTA TRANSISTOR B1ACDF000006 (GC) Q601,02 2SC5398RSTA TRANSISTOR B1AACF000059 Q605-10 2SC3327A TRANSISTOR Q612 UN411FTA TRANSISTOR UNR411F00A Q701 2SD2374PQAU TRANSISTOR 2SD23740J1AU Q702 2SB1548PQAU TRANSISTOR 2SB15480J1AU Q703,04 2SD2137PQTA TRANSISTOR 2SD21370PA (GC)
  • Page 42 Ref. No. Part No. Part Name & Description Remarks R509-12 ERDS2FJ470 1/4W 47 R544 ERDS2FJ103 1/4W 10K R546,47 ERDS2FJ183 1/4W 18K R548 ERDS2FJ102 1/4W 1K (GN) R551 ERDS2FJ183 1/4W 18K R552 ERDS2FJ473 1/4W 47K R553,54 ERDS2FJ562 1/4W 5.6K (GN) R555 ERDS2FJ223 1/4W 22K R556...
  • Page 43 Ref. No. Part No. Part Name & Description Remarks R649-52 ERDS1FJ100 R683-86 ERDS2FJ102 1/4W 1K R687,88 ERDS2FJ152 1/4W 1.5K R691 ERDS1FJ151 (GC) R691 ERDS1FJ680 (GN) R692,93 ERDS2FJ102 1/4W 1K R694 ERDS2FJ223 1/4W 22K R695 ERDS2FJ471 1/4W 470 R696 ERDS2FJ473 1/4W 47K R707 ERD2FCJ4R7 R708...
  • Page 44 R794 ERDS2FJ473 1/4W 47K...
  • Page 45 Ref. No. Part No. Part Name & Description Remarks R794A ERQ16NKW1R0E (GC) R795 ERDS2FJ392 1/4W 3.9K R796,97 ERDS2FJ2R2 1/4W 2.2 (GC) R797 ERDS2T0T CHIP JUMPER (GN) R901 ERDS2FJ821 1/4W 820 R902 ERDS2FJ102 1/4W 1K R903 ERDS2FJ122 1/4W 1.2K R904 ERDS2FJ152 1/4W 1.5K R905 ERDS2FJ182...

  • Page 46: Cabinet Parts Location

    Ref. No. Part No. Part Name & Description Remarks R975 ERDS2FJ223 1/4W 22K R976 ERDS2FJ104 1/4W 100K R986 ERDS2FJ152 1/4W 1.5K R987,88 ERDS2FJ102 1/4W 1K R990 ERDS2FJ104 1/4W 100K R991 ERDS2FJ473 1/4W 47K R993,94 ERDS2FJ104 1/4W 100K R995 ERDS2FJ221 1/4W 220 R996,97 ERDS2FJ151 1/4W 150...
  • Page 47 F010400000YM/KH 2001 Matsushita Electric Industrial Co., Ltd. All rights reserved. Unauthorized copying and distribution is a violation of law.
  • Page 48 Tuner/amplifier 1 Standby/on switch ( Í/I) Press to switch the unit from on to standby mode or vice versa. In 2 345 6 standby mode, the unit is still consuming a small amount of power. DIGITAL 2 Standby indicator ( Í) S.WOOFER When the unit is connected to the AC mains supply, this indicator lights VOLUME...
  • Page 49 Z120 TUNER UNIT (RAN0004MM-2) FM ANT AM ANT +B(FM) RF AMP MIXER COIL COIL +B(FM) FM IF +B(FM) BUFFER FM OSC FM / AM I F AMP, +B(FM) DET / AM OSC, MIX / FM MPX (LA1833NM) DECODER BUFEER PHASE STEREO PILOT SWITCH...
  • Page 50 W501 TUNER L/C TUNER Rch A.GND Lch IN Rch IN +B(10V) SUR L SUR R To SOUND PROCESSOR (SH-EH770) BLOCK DIAGRAM -B(-10V) V.GND D.GND CE/REQ DATA CT.GND SH FL1 From POWER TRANSFORMER SH FL2 SYNC TA2011S IC401 Q401 MIC2 VR401 (MIC VOL) MIC1 C2BBFD000297...
  • Page 51 Q609 Q607 (Q610) (Q608) MUTING MUTING BU4053BCFE2 Q606 IC201 SIGNAL SELECTOR MUTING Q605 MUTING SW CONT. Q902 Q612 MUTING MUTING CONT. CONT. X901 X902 Z901 (6MHz) (32.7kHz) (REMOTE VR901 SENSOR) (VOLUME) C2BBFD000297 IC901 SYSTEM CONTROL / FL DRIVE 30~37 38~45, D934,936 47~50 52~71,...
  • Page 52 PHONES R ch RSN311W64B IC601 POWER AMP (18) D974 D601 POWER CONTROL CIRCUIT (25) SURROUND CENTER SPEAKERS (12) Q503,D558 SWITCH- POWER CONTROL/ PROTECTION CIRCUIT Q551,554, SIGNAL LEVEL DET. D907 For [GC] area. Q601,602 D602 PRO- D906 MOTOR TECTOR DRIVE Q553,556, FAN MOTOR C2BBFD000297 IC901...
  • Page 53 Q702,705 REGULATOR T701 /STABILIZER D702,704, 752,754,755 For [GC] area. S701 (VOLT ADJ) D701,703, 751,753,761 Q703,704 (For [GC] area.) AC IN L701 Q710 (For [GN] area.) REGULATOR Q723 RLY702 REGULATOR Q701 Z701 REGULATOR AC IN D717~720 Q711,725 Q791 REGULATOR RELAY /STABILIZER DRIVE Q707 D705...
  • Page 54 OPERATION P.C.B. VR901 (VOLUME) W902B S913 DIGITAL C414 S.WOOFER R918 C902 C915 R932 R956 R957 CN904 R919 R987 Q902 D961 D973 W901B C903 FL901 S915 R960 R939 (ECHO) R986 S914 (KARAOKE) S912 (TUNER/ R994 BAND) S911 (TUNING R911 IC901 R940 S908 C925 S910...

  • Page 55: Mic Jack P.c.b

    AC IN P.C.B. For [GC] area. R794 R795 Q791 E C B RL702 T702(Power transformer) R780 D500 R773 R774 Q726 E C B C754 C758 Q727 R775 C791 E C B C757 R777 CN602 CN751 C753 Z701 CN601 C634 R646 L701 C624 L604...
  • Page 56 AC IN P.C.B. For [GN] area. R794 R795 Q791 D740 E C B RL702 T702(Power transformer) D500 R773 R774 Q726 E C B C754 C758 C791 R777 CN602 C753 W2/W3 Z701 CN601 C634 R646 L701 C624 L604 C644 L603 C651 C646 C625 C652...
  • Page 57 MAIN P.C.B. Q723 C740 D737 W902A CP101 CN781 Q609 For [GC] area. R693 E C B R692 W501 For [GN] area. E C B R597 Q553 Q557 Q610 R598 C559 R558 R568 R605 R606 C555 E C B E C B R617 R566 C556...
  • Page 58 POWER POWER TRANSFORMER TRANSFORMER (A) P.C.B. For [GC] area. (B) P.C.B. For [GC] area. CN701 R794A T701(Power transformer) CN714 CN702 CN703 CN715 W721B W722B CN704 CN716 CN705 CN717 CN706 CN707 CN718 CN708 R791 CN719 CN709 R792 CN720 CN710 (REP3115C-M) BROWN S701 (VOLT ADJ) ORANGE...
  • Page 59 SCHEMATIC DIAGRAM-1 NOTE: :POSITIVE VOLTAGE LINE The number which noted at the connectors on the schematic diagram as :AUDIO SIGNAL LINE "SCHEMATIC DIAGRAM-1" or "SCHEMATIC DIAGRAM-2" OPERATION CIRCUIT :MIC SIGNAL LINE indicates the schematic diagram serial number located on the left corner in the schematic diagram. FL901 (A2BB00000084) FL DISPLAY 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50...

  • Page 60: Schematic Diagram

    SCHEMATIC DIAGRAM-2 : POSITIVE VOLTAGE LINE : NEGATIVE VOLTAGE LINE -30.1V A B C D E F G H I J K L M N O P Q R S T U V W X 5.1V Q901 UN4212TA RESET -30.1V -25.6V FM / AM -29.3V...
  • Page 61 SCHEMATIC DIAGRAM-3 OPERATION CIRCUIT : POSITIVE VOLTAGE LINE : NEGATIVE VOLTAGE LINE :AUDIO SIGNAL LINE :MIC SIGNAL LINE Z901 R941 B3RAD0000028 (REMOTE SENSOR) Q902 UN411FTA MUTING CONT. R974 5.1V 3.3V 3.3V VR901 R946 EVQVBXFK124B (VOLUME) A B C R943 R961 W902B R945 R962...
  • Page 62 SCHEMATIC DIAGRAM-4 : POSITIVE VOLTAGE LINE : FM SIGNAL LINE :MIC SIGNAL LINE MAIN CIRCUIT : NEGATIVE VOLTAGE LINE : AM SIGNAL LINE :AUDIO SIGNAL LINE 7.6V -10.4V W501 TUNER Lch/C TUNER Rch R511 R509 R597 C659 R631 A.GND 2.2K 16V10 3.9K Lch IN...
  • Page 63 SCHEMATIC DIAGRAM-5 : POSITIVE VOLTAGE LINE : NEGATIVE VOLTAGE LINE :AUDIO SIGNAL LINE 7.6V -10.4V IC601 RSN311W64B POWER AMP -51.4V 54.1V -29.7V 29.4V -0.2V -29.3V 28.9V -59.5V 59.5V C648 1000P R612 R620 C610 120K R611 C609 R619 120K R610 150K C612 R622 120K...

  • Page 64: Power Supply Circuit

    SCHEMATIC DIAGRAM-6 : POSITIVE VOLTAGE LINE MAIN CIRCUIT FAN MOTOR : NEGATIVE VOLTAGE LINE :AUDIO SIGNAL LINE 7.6V 4.7V FAN ON:0V R566 JK551 0.5V FAN ON:0V R568 C556 0.5V 16V10 R570 2.2M Q557 C552 R559 2SA1995RSTA 7.6V Q556 0.01 4.7K -10.4V MOTOR DRIVE 2SC5398RSTA...
  • Page 65 SCHEMATIC DIAGRAM-7 : POSITIVE VOLTAGE LINE : NEGATIVE VOLTAGE LINE :AUDIO SIGNAL LINE L605 SPEAKERS R649 JK601 HF(6 L602 R640 LF(8 L606 R650 JK602 HF(6 LF(8 L601 CP601 R639 C OUT C OUT AC IN CIRCUIT(CN601) on SCHEMATIC DIAGRAM-8,9 SUR L OUT SUR L OUT SUR R OUT SUR R OUT...

  • Page 66: Power Transformer

    SCHEMATIC DIAGRAM-8 : POSITIVE VOLTAGE LINE AC IN CIRCUIT For [GN] area. : NEGATIVE VOLTAGE LINE CN601 JK603 C OUT CENTER(8 ) C OUT L604 MAIN CIRCUIT(CP601) R644 on SCHEMATIC DIAGRAM-7 SPEAKERS R ch SUR L IN L603 SUR L IN SURROUND(8 ) SUR R IN R643...
  • Page 67 SCHEMATIC DIAGRAM-9 : POSITIVE VOLTAGE LINE AC IN CIRCUIT For [GC] area. : NEGATIVE VOLTAGE LINE CN601 JK603 C OUT CENTER(8 ) C OUT L604 MAIN CIRCUIT(CP601) R644 on SCHEMATIC DIAGRAM-7 SPEAKERS R ch SUR L IN L603 SUR L IN SURROUND(8 ) SUR R IN R643...
  • Page 68 SCHEMATIC DIAGRAM-10 :FM SIGNAL LINE :AM SIGNAL LINE Z101 TUNER UNIT(RAN0004MM-2) :POSITIVE VOLTAGE LINE :FM OSC SIGNAL LINE :AM OSC SIGNAL LINE 2SC2059 FM MIXER 2SK360 0 ~ 220 RF AMP FM ANT 2SC2413 BUFFER AMP AM ANT 0.47 LOOP 330P ~ 560P 0.56 H...
  • Page 69 SCHEMATIC DIAGRAM-11 :POSITIVE VOLTAGE LINE :FM SIGNAL LINE :AM SIGNAL LINE :AM OSC SIGNAL LINE 270K ~ 270K ~ 680K 1000P 680K 1000P 2SC2413 2SC2413 DTA114 POWER SUPPLY FM IF AMP FM IF AMP (FM:ON) LA1833NM FM/AM IF AMP, DET/AM OSC,MIX/FM MPX 6.8K 6.8K 0.47...
  • Page 70 BU4053BCFE2 C2BBFD000297 RSN311W64B TA2011S UN411FTA 2SB1417PQTA UN4211TA 2SD2137PQTA UN4212TA ....... 2SD2144STA 2SA1995RSTA 2SC3940AQSTA...
  • Page 71 For [GC] area..W721 POWER W722 TRANSFOR-MER (A) P.C.B. T701 (Power transformer) POWER TRANS- FORMER (B) P.C.B. 1 . 3 T702 (Power transformer) CN751 CN602 AC IN P.C.B. CN601 CENTER/ AC IN SURROUND SPEAKERS...

  • Page 72: Operation

    MIC1 MIC2 To SOUND PROCESSOR SPEAKERS For [GC] area. FAN MOTOR MIC JACK JK551 P.C.B. Z101 W904B CP601 1 . . 4 TUNER UNIT CP101 MAIN P.C.B. CP602 ..W501 ..W722A .

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