Mitsubishi HS-U778 Specifications Page 1

SPECIFICATIONSTape FormatPower SourcePower ConsumptionVideo Signal SystemVideo Recording SystemLuminanceColor SignalHi-Fi AudioRecording SystemLinear

-6-4. Removal of DECK ASSY1. Remove the Top Cover.(Refer to Para. 1 of the DISASSEMBLY.)2. Remove the Front Panel.(Refer to Para. 2 of the DISASSEMBLY

-7-CAUTION: BEFORE ATTEMPTING TO REMOVE ORREPAIR ANY PCB, UNPLUG THE POWERCORD FROM THE A.C. SOURCE.LOCATION OF PRINTED CIRCUITBOARDSNote :• Take caut

-8-3. PCB-MAIN1. Remove the Bottom Panel.(Refer to Para. 3 of the DISASSEMBLY.)2. Remove the DECK ASSY.(Refer to Para. 4 of the DISASSEMBLY.)3. Remove

-9-Soldering PencilTweezersSolderChipPatternCHIP PARTS REPLACEMENTSome resistors, shorting jumpers (0Ω resistor), ceramiccapacitors, transistors and d

-1-Lightly apply the clothon the UPPER DRUMASSY. Do not move the cloth.Video HeadCleaningCloth!1!2wuy!0 erqtio!3Fig. 1-11. DECK CleaningThe following

-2-aabbFELT RINGCLEANING ARMFig. 2-1aaSTAY PLATEFig. 2-22. Replacement of Major Parts2-1. CLEANING ARM, FELT RINGSET POSITION : Normal(Removal)1. Rele

-3-BACaHole in MAIN PLATE ASSYBOTTOM ASSYWORM WHEELARM (SP)LiftPull outFig. 2-3-1bcdeMAIN PLATE ASSYGroove of MAINPLATE ASSYSide ViewGREASE(MULTEMP AC

-4-aINSERT GUIDE (TU)Fig. 2-4aINSERT GUIDE (SP)Fig. 2-52-4. INSERT GUIDE (TU)SET POSITION : NormalRemove the following parts before replacing the INSE

-5-cdabAMAIN PLATEASSYF/L ARM ASSYF/LBEARINGGREASE(MULTEMP AC-DM)ARM (SP)ARM (TU)GREASE(MULTEMP AC-DM)acbREC LEVERRECSPRINGREC HOLDERFig. 2-6Fig. 2-72

-6-aaLEAD CONNECTORA/C HEAD UNITHeadFig. 2-82-8. A/C HEAD UNITSET POSITION : Normal(Removal)1. Remove the LEAD CONNECTOR of the A/C HEADUNIT shown in

-2-CONTENTS– FILE “COVERPGE” –SPECIFICATIONS ...1CONTENTS...

-7-2-10.SENSOR COVER (TU) SET POSITION : Normal(Removal)1. Release the catch (a) of the SENSOR COVER (TU)shown in the Fig. 2-10 to remove the SENSORCO

-8-2-12.REV UNIT (TU),REV UNIT (SP)SET POSITION : Upside down(Removal)1. Release the two catches (a) of the REV UNIT (TU)shown in the Fig. 2-12 to rem

-9-aAREEL BELTPULLEY BUSHTHRUST WASHERBELT PULLEYPull in the directionof the Arrow (A) toremove it from theSHIFT LEVER.SHIFT SLIDERPULLEY GEAR ASSYSLI

-10-SLIP ADJUSTERCenter of theBELT PULLEYIDLER UNITMatch the Lug of theSLIP ADJUSTER withthe Center Notch ofthe IDLER UNIT.Apply GREASE(PG-641)to the

-11-2-15.CAPSTAN BRAKE SPRING, CAPSTANBRAKE ASSYSET POSITION : Upside down(Removal)1. Remove the CAPSTAN BRAKE SPRING shown in theFig. 2-15.2. Remove

-12-bbcaaLOADING MOTOR ASSY FC HOLDERLOADINGWORMMOTORHOLDERLUG TERMINALWORM WHEELFig. 2-16-1WORM WHEEL LOADING WORMApply GREASE (MULTEMP AC-DM) to the

-13-aPINCH ARMCAPPart PartPINCH ASSYMAIN CAMRibABFig. 2-17GREASE(MULTEMP AC-DM)F/L PLATEDOOR ARMARM (TU)MAIN CAMGREASE(MOLYKOTEG PASTE)MAIN PLATEASSYG

-14-Hole MAIN CAMF/L PLATEBossFig. 2-18-2BAbbaaabbBRAKE CAM PLATEMAIN CAMFig. 2-19-170mm40mm130mm99mmBRAKE CAM PLATEBackApply GREASE (MOLYKOTE G PASTE

-15-abcABMAIN PLATE ASSYGUIDE LAMPRemoving Direction Installing DirectionFig. 2-20CBRAKE SPRINGCatchInsert the BRAKE SPRINGunder the Catch.BRAKE (TU)F

-16-AaMAIN CAMBRAKE LEVERGREASE(MULTEMP AC-DM)GUIDE ARM (TU)BackGREASE(MULTEMP AC-DM)MAIN PLATE ASSYLB PINMAIN PLATE ASSYHoleMAIN CAMSHAFTFLANGEof the

-3-CONTENTS3-2-1 GUIDE ROLLER Adjustment Check ...313-2-2 Height Adjustment ofGUIDE ROLLER (SP) ...313-2-3 Hei

-17-L/D LOCK LEVERFig. 2-22bacBELT HOLDERBRAKE BELT (SP)BELT LEVERREEL DISK (SP side)Fig. 2-232-22.L/D LOCK LEVERSET POSITION : NormalRemove the follo

-18-abATENSION ARMREEL DISK (SP side)TENSIONSPRINGTENSAXISHOLDERMAIN PLATE ASSYTHRAUSTWASHERTENSIONLEVERGREASE(MULTEMPAC-DM)aBELT LEVERBELT ADJUSTERFi

-19-aaBRAKE BELT (TU)BRAKE (TU)REEL DISK (TU side)Fig. 2-26(Installation)1. Apply OIL (FLOIL 948P) [859D154O20] to the parts onthe MAIN PLATE ASSY spe

-20-(Installation)Note : Install the BRAKE BELT (TU) so that its Felt Sidetouches the REEL DISK (TU side).The GREASE applied to the BRAKE CAM PLATEand

-21-CHARGE SPRINGCHARGE ASSYSWING LEVERREEL DISK (SP side)Both Sides(Front/Back)MAIN PLATE ASSYabcBackFrontFig. 2-292-29.CHARGE SPRING, SWING LEVER,CH

-22-LOADING ARMASSY (TU)MarkLOADING ARMASSY (SP)LOADING ARM ASSY (TU)Apply GREASE (MULTEMP AC-DM) to the parts .Fig. 2-30-3Fig. 2-30-2(Installation

-23-A/L LEVERBossFLANGE ofLOADING ARM ASSY (SP)MarkPart withOblique LinesA/L LEVERBackApply GREASE (MOLYKOTE G PASTE) to the parts .Fig. 2-31-2Fig

-24-TAPE GUIDE ASSY (SP) TAPE GUIDE ASSY (TU)Fig. 2-32-1GUIDE CATCHER (SP)GUIDE CATCHER (TU)Front ofMAIN PLATE ASSYBack ofMAIN PLATE ASSYApply GREASE

-25-BADRUM CLAMPERHook here to attachDRUM CLAMPERto DRUM ASSY.DRUM ASSYRemovingDirectionInstallingDirectionabDRUM ASSY withDRUM CLAMPERLEAD CONNECTORM

-26-abbcDRUM MOTORSTATORROTOR CASESide View of END RINGThis side down. LEADCONNECTORBRUSHSPRINGBRUSHEND RINGUPPERDRUM ASSYSPACERLOWERDRUM ASSYMark usi

-4-JSTCLKLIN-INLIN-OUTLMUTELPMODMOTORVNLOSCPBPCPCBPGPLLPRTPSAVEPSLEDPSYNCPWSVPWVQHQVRECREC2RECPBCRESRESPCMREWRISRMSDETRXDSAPINDSCLKSCRSISLDSPSSSSVSYNC

-27-BROTOR CASEUPPER DRUMASSYFig. 2-34-3ALockSTAY PLATEWORMWHEELHook ofBOTTOM ASSYLockFig. 2-35-1AEND RINGRear Line of MAIN PLATE ASSY Fig. 2-34-2(Ins

-28-SILICON COMPOUND(SC102)MAIN PLATE ASSYFig. 2-35-3aAWORM WHEELArrow GUIDE ARM (TU)CAPSTAN MOTORBFig. 2-35-2(Installation)1. Apply SILICON COMPOUND

-29-FLYWHEEL (SP)IMPEDANCE UNIT (SP)aabSSW HOLDERSSW SLIDERaa2-36.IMPEDANCE UNIT (SP),FLYWHEEL (SP)SET POSITION : Normal(Removal)1. Unfasten the two c

-30-3. Interchangeability Adjustmentof the MechanismNote 1 : Tracking may need to be preset duringinterchangeability adjustment of the mechanism.Digit

-31-3-2. Check and Adjustmentof the FM Envelope3-2-1. GUIDE ROLLER Adjustment check1.Play back an alignment tape (NM6KE2 : 859C339O90).2. Preset the t

-32-3-2-4. Coarse Adjustment of Phase1.Play back an alignment tape (NM6KE2 : 859C339O90).2. Preset the tracking.3. Observe the FM Waveform after perfo

-33-3-2-6. Tape Running Conditionat the GUIDE ROLLERs (Check 1)1. Play back an Alignment Tape.[NM6KE2: 859C339O90]2. Confirm visually that there is a

-34-3-3. A/C HEAD Adjustment 3-3-1. Slant Adjustment of A/C HEAD1. Play back a blank tape.2. Slowly turn the slant adjustment Screw C shown in theFig.

-35-3-4. Phase Adjustment1.Play back an alignment tape (NM3KE6 : 859C339O50). 2. Preset the tracking.3. Loosen the Screws D and E shown in the Fig. 3-

-36-4. Servicing for Tape Jamduring the Loading Process1. Remove the tape if the mechanism part is locked duetangled tape.2. Rotate the WORM WHEEL of

-1-INTRODUCTIONThis manual provides service information for the adjustmentsof mechanical and electrical operations.Due to design modifications, the se

-37-1. Short-circuit the cathode side of D927 and the GND of the DECK ASSY using the jig shown in Fig. 2.2. Remove the DECK ASSY.3. Connect TP5X and T

-1-TP2ATP5ATP5BTP2HLOCATIONSPCB-MAIN (Component side) REARELECTRICAL ADJUSTMENTSPerform only the alignments required. If proper equipment is not avail

-2-Adjustment purpose[ Servo circuit ]1. Playback SwitchingPointSymptom whenincorrectly adjustedMeasuring instrument and conditionTest pointEXT trigge

-1-PARTS LIST1. CABINET ASSEMBLYrw1!2!18367t!09!3

ITEMNO.PARTS NO. PARTS NAME DESCRIPTION: Critical Component-2-1 968C049O03 TOP COVER ASSY2 669D221O40 SCREW 4 × 12 46LA0053 572D385O10 F/L SPRING4 752

-3-!12244!9!8!6!5!4!3!2!7A1B32. PACKING PARTSACCESSORYAB

ITEMNO.PARTS NO. PARTS NAMEPACKING PARTSACCESSORYDESCRIPTION: Critical Component-4-1 831D190O30 PACKING SHEET 800X8002 803A570O10 CUSHION3 802B827O30

DECK ASSEMBLY

M-025M-026G-015G-016G-023G-024G-032G-033G-203G-045G-047G-048G-049G-054G-212G-054G-212G-084G-104G-062G-201G-063G-201G-064G-065G-067G-071G-201G-201G-077

ITEMPARTS NO.ADDRESSPARTS NAME DESCRIPTIONQt.∗A-019 669D224O90 K G-3 SCREW 2.6 × 51A-021 597D568O10 G-2 FLYWHEEL (SP) 1A-022 948B404O09 G-1 DRUM ASSY

-2-2. Hot CheckThe test sequence, with reference to the measuringcircuit in the figure is as follows:(1) With switch S1 open, connect the VCR to the m

G-019G-066G-216G-211G-096G-061G-025G-017G-018G-088G-201G-081G-093G-031G-035G-101G-043G-034G-057G-056G-212G-060G-044G-094G-201G-042M-014M-03112345678AB

ITEMPARTS NO.ADDRESSPARTS NAME DESCRIPTIONQt.∗A-028 621C810O10 A-5 SSW HOLDER 1A-029 622D837O10 A-4 SSW SLIDER 1G-017 948D089O01K H-4LOADING ARM ASSY

INTEGRATED CIRCUITSIC120 275P344O30 MOS IC M35053-051FPIC150 272P583O20 IC NJM2533MIC151 272P325O40 IC NJM2535MIC2A0 270P827O10 IC JCP8017-NSAIC2A1 27

Q922 260P562O40 TRANSISTOR 2SA952-KQ927 260P586O20 TRANSISTOR 2SB892-TQ928 260P559O40 TRANSISTOR 2SC1740S-R,SQ929 261P036O10 TRANSISTOR 2SB1548Q930 26

TRANSFORMERST901 350P717O60 POWER TRANSFORMERVARIABLE RESISTORS127C510O80 SEMIFIXED RESISTOR 1/5W B10kΩ +-25%R901 109C010O50 SOLID RESISTOR 1W 2.2MΩ-K

R2061 103P409O50 CHIP RESISTOR 0.1W 0Ω (2125)R2062 103P409O50 CHIP RESISTOR 0.1W 0Ω (2125)R2063 103P409O50 CHIP RESISTOR 0.1W 0Ω (2125)R2064 103P409O5

R6E5 103P472O90 CHIP RESISTOR 1/10W 1.5kΩ-FR6E6 103P472O50 CHIP RESISTOR 1/10W 1kΩ-FR6E7 103P472O50 CHIP RESISTOR 1/10W 1kΩ-FR6E8 103P472O50 CHIP RESI

C126 141P132O10 CHIP CAPACITOR B50V 0.01µF-KC127 141P132O10 CHIP CAPACITOR B50V 0.01µF-KC128 154P332O70 CHIP CAPACITOR CH50V 47pF-JC130 141P130O30 CHI

C358 141P131O70 CHIP CAPACITOR B50V 4700pF-KC379 181P212O60ELECTROLYTIC CAPACITOR04W 16V 47µF-MC3A7 141P139O30 CHIP CAPACITOR B25V 0.1µF-KC3A9 141P139

C6034 181P219O90ELECTROLYTIC CAPACITOR04W 50V 3.3µF-MC6035 181P219O90ELECTROLYTIC CAPACITOR04W 50V 3.3µF-MC6036 141P132O10 CHIP CAPACITOR B50V 0.01µF-

-3-Connecting separate antennas (UHF/VHF)Connecting the TelevisionTo connect separate UHF/VHF antennas to the VCR:1. Disconnect the antennas from the

YNRDETAILEMPHN.LEMPHMAINEMPHPMMOD13L-DETVCAMAINCONV160 58MIXIC2A0Luminance/ChromaCCDLPFPCB-MAINDECKJ6004V-IN114LAGLEADLPF(U77802041)BPFCLPFB-1MAINCONV

(U77802042)RotaryTransVideoHeadHH2H-COM2H-R2H-L 6H-COM6H-R6H-L89 88 86 94 91Head AmpFM AGCPEQIC2A0Luminance/ChromaSIMPLESDLG,EQYLPFSQPBEQUALIZERNLDE-E

L-OUTR-OUTRotaryTransA-RA-L53HIFI HeadsRECONMHMIXRECLPFVCOLIMITTERRLHIFI RECLINEAR PLAYL-INL-CHANNELR-CHANNELPCB-MAINR-IN29414R-A-IN-LR-A-IN-RA-IN1-RA

Q5A5Q5A3Q5B1BackUp37 43826From IC3A0 AMODE7980SU-SENSTU-SENSPRT3Q5A0Q5A1SupplySensorTake UpSensorProtect of Power(SW5-1,SW5-2,SW12)PWSV Vcc

N1HS-U778MCMRMHOSMSJPJQDDDAMVSWMQMTMDMWSUDCSTSVJRMUMPBBMAMLMFPCB-INTERCONNECTwPCB-MAINePCB-MAINPCB-MAINPRINTED CIRCUIT BOARDPARTS LAYOUTtrPCB-JACKoiPC

N2HS-U778STBY5R901G12JP910C901RV901R902Q927C905F901BBC918L904D909T901D902C925R903R907JP901R967STBY5SW5-2R913D908D960PC901C917C910CBVC9Y1R904SW5-2C937D

N3HS-U778INPUTOUTPUTCONTROLLER4SCK3CSS IN5DATACONTROLLERADDRESSCONTROLLERDISPLAYCONTROLREGISTERDISPLAY RAMTIMINGGENERATORDISPLAY CHARACTER ROMCLOCKGEN

N4HS-U778Q3A0LIN-INTP3SC3F6IC3A0C3A7LIN-OUTEECONV-AUDIOHF-RECD3A2D3A0AMODED3A1TU-INC3F8C3F5A-OUT-RA-OUT-LAENVMUTEI2C-CLKI2C-DATAC3F2C3F7C3C0C3B9C3B8C3

N5HS-U778C2D9C2E2Y-FROM-YCAREC-CALC-DETR2F1R2C0Q2E0C2H4IC2A1IC2A0S-DETQ2B0C2G7C2G9SW5-1C2J0R2J0Q2A0C2J1TP2BR2F9C2G4R2D3C2G5L2B2Q2B3Q2B1Q2B2R2E0R2D9R2E

N6HS-U778WORD ADDRESSBUFFERSSTART/STOPLOGICCONTROL LOGICCOLUMNDECODERSXDECE PROM2DATA IN STORAGEHIGH VOLTAGE/TIMING CONTROLSENSE AMPSSHIFT REGISTERSD

-4-1. Removal of Top Cover1. Remove the two Top Cover fastening screws (a) shownin Fig. 1 and remove the Top Cover in the directionshown by arrow.2. R

N7HS-U778SERIALI/F6D IN5D OUT8CLK9STBOSC44OSCTIMING GENERATORKEY SCANDISPLAY MEMORY16Bits X 11WordsKEY DATA MEMORY(4 X 6)10 ~ 13KEY 1KEY 444 Bit LATCH

N8HS-U7784Vin 2SW1Vin 1NC321BIAS8765GND Vout V NCBUFFER+58KΩ58KΩIC6001,IC6002 NJM2520MNot EmployedIC6001Q6002R6022Q6003J6014J6006JPC6301R6301R6304R60

N9HS-U778Q6A2C6A0C6A2C6A3C6A5C6A1PBC6A6C6A7SWR6A1SW5R6A4PB-CFSCYCS-CYCS-YR6B7YCS-INGNDR6B1R6B2R6A0D6A3SUR6A2R6A6C6A8C6A9C6B0C6C7C6B1C6B2C6B3R6B0R6A9L6

N10HS-U778PS COMBAD212169ADNON RELATION DET1H DLYCNRY COMB1H DLYNTSC 3L LOGI.COMBPAL 3L LOGI.COMBFILTER COMB1H DLYYC TIM.ADJDADAVY INC IN C OUTV OUT44

N11HS-U77821F3+11++K+3+166449+17+324833+3BE++EBBE++++9+5155606570758095908581++A-OUT765++121110+++++EE+++8712+++++146++1++++++353130252015105+3121A+++

-5-a3. Removal of Bottom Panel1. Remove the two fastening screws (a) shown in Fig. 2.2. Turn the set upside down as shown in Fig. 3.3. Slide the Botto