JVC HR-S3800U Service Manual Download

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SERVICE MANUAL

No. 82792

March 2000

HR-S3800U/S4800U

SPECIFICATIONS

VIDEO CASSETTE RECORDER

This service manual is made from all recycled paper.

TV CH +

–

TV CH –

CANCEL

TIMER

START

STOP

DATE

PLAY

REW

REC

STOP

SHUTTLE

PLUS

PAUSE

MEN

POWER

TV/VCR

C.RESET

DBS

DAILY(M-F)

AUX

WEEKLY

PROG
CHECK

PROG

SP/EP

SKIP SEARCH

DISPLAY

A. MONITOR

CABLE/

DBS

EXPRESS PROGRAMMING

MULTI BRAND

REMOTE CONTROL UNIT

MBR SET

A/B

VIDEO (MONO)L—AUDIO—R

S-VIDEO

S-VHS ET

REW

POWER

VCR

REC

PAUSE

STOP/EJECT

PLAY

GENERAL

Power requirement

: AC 120 V

, 60 Hz

Power consumption

Power on

: 20 W

Power off

: 2.5 W

Temperature

Operating

: 5°C to 40°C (41°F to 104°F)

Storage

: –20°C to 60°C (–4°F to140°F)

Operating position

: Horizontal only

Dimensions (W x H x D) : 400 x 94 x 281 mm

(15-3/4" x 3-3/4" x 11-1/8")

Weight

: 3.4 kg (7.5 lbs)

Format

: S-VHS/VHS NTSC standard

Maximum recording time

: 210 min. with ST-210 video cassette

: 630 min. with ST-210 video cassette

VIDEO/AUDIO

Signal system

: NTSC-type color signal and EIA

monochrome signal, 525 lines/60
fields

Recording/Playback
system

: DA-4 (Double Azimuth) head

helical scan system

Signal-to-noise ratio

: 45 dB

Horizontal resolution

VHS

: 230 lines

S-VHS

: 400 lines

Frequency range

Normal audio

: 70 Hz to 10,000 Hz

Hi-Fi audio

: 20 Hz to 20,000 Hz

Input/Output

: RCA connectors (IN x 2, OUT x 1)

S-video connectors (IN x 2, OUT x 1)

TUNER

Tuning system

: Frequency-synthesized tuner

Channel coverage

VHF

: Channels 2–13

UHF

: Channels 14–69

CATV

: 113 Channels

RF output

: Channel 3 or 4 (switchable;

preset to Channel 3 when
shipped) 75 ohms, unbalanced

TIMER

Clock reference

: Quartz

Program capacity

: 1-year programmable timer/8 programs

Memory backup time

: Approx. 3 min.

ACCESSORIES

Provided accessories

FOR HR-S4800U : Infrared remote control unit,

“AA” battery x 2,
Audio/video cable,
S-video cable (4-pin),
S-VHS ET labels,
Controller

FOR HR-S3800U : Infrared remote control unit,

“AA” battery x 2,
Audio/video cable,
S-video cable (4-pin),
S-VHS ET labels,

Specifications shown are for SP mode unless specified otherwise.
E. & O.E. Design and specifications subject to change without notice.

Summary of Contents for HR-S3800U

Page 1: ...o cassette EP 630 min with ST 210 video cassette VIDEO AUDIO Signal system NTSC type color signal and EIA monochrome signal 525 lines 60 fields Recording Playback system DA 4 Double Azimuth head helical scan system Signal to noise ratio 45 dB Horizontal resolution VHS 230 lines S VHS 400 lines Frequency range Normal audio 70 Hz to 10 000 Hz Hi Fi audio 20 Hz to 20 000 Hz Input Output RCA connector...

Page 2: ... 1 5 MECHANISM SERVICE MODE 1 5 1 5 1 How to set the MECHANISM SERVICE MODE 1 5 1 6 EMERGENCY DISPLAY FUNCTION 1 6 1 6 1 Displaying the emergency information 1 6 1 6 2 Clearing the emergency history 1 6 1 6 3 Emergency content description 1 7 1 6 4 Emergency detail information 1 1 8 1 6 5 Emergency detail information 2 1 9 1 7 SYSCON CIRCUIT 1 10 1 7 1 Syscon CPU pin function IC3001 1 10 2 MECHANI...

Page 3: ...re specified for compliance with recognized codes pertaining to X ray emission Consequently when servicing these products replace the cath ode ray tubes and other parts with only the specified parts Under no circumstances attempt to modify these circuits Unauthorized modification can increase the high voltage value and cause X ray emission from the cathode ray tube 12 Crimp type wire connector In ...

Page 4: ...ter to measure across both terminals of load Z See figure 9 and following table 2 5 Grounding Class 1 model only Confirm specified or lower grounding impedance between earth pin in AC inlet and externally exposed accessible parts Video in Video out Audio in Audio out or Fixing screw etc Measuring Method Connect milli ohm meter between earth pin in AC inlet and exposed accessible parts See figure 1...

Page 5: ... CN7108 S3 S JACK board assembly WR3b SUPPORTING TAPE SIDE NOTE 3c FRONT PANEL BACK SIDE S4a WR4b WR4a 4 CN1 a c CN1 b FOIL SIDE NOTE 3c FOIL SIDE NOTE 3c DRUM SHIELD S4b S4a L4a L4b P4 ROLLER ARM ASSEMBLY INERTIA PLATE NOTE When installing the DRUM assembly secure the screws S4a in the order of a b c ...

Page 6: ... direction as indicated by Fig 3 to release them When pushing the levers do it in the order of A B B A When the holder has been lowered turn the pulley until the cassette holder is securely in place without allowing any up down movement Procedures for Lowering the Cassette holder assembly As the mechanism of this unit is integrated with the Housing assembly the holder must be lowered and the two s...

Page 7: ...de turn the set to the normal position Fig 1 4 2 Fig 1 4 1 5 Remove the Main board and Mechanism assemblies to gether while holding the edge of the Main board assem bly At this stage be careful of the power cord and prongs of the jacks on the back side See Fig 1 4 2 D C JACK board assembly CN7108 1 4 SERVICE POSITION In order to facilitate diagnosis and the repair of the Mecha nism assembly this u...

Page 8: ...cedures for Lowering the Cassette holder as sembly on pages 1 3 of 1 3 DISASSEMBLY ASSEMBLY METHOD 6 The cassette holder lowers and when the loading has completed the mechanism enters the desired mode 1 5 MECHANISM SERVICE MODE This model has a unique function to enter the mechanism into every operation mode without loading of any cassette tape This function is called the MECHANISM SERVICE MODE MA...

Page 9: ...ergency 3 Mechanism sensor information at the moment of emergency 4 Mechanism mode position at the moment of emergency NOTE For the emergency detail information 1 see 1 6 4 Emergency detail information 1 3 Transmit the code 59 from the Jig RCU once again The FDP shows the emergency detail information 2 in the form of 5 6 7 5 Type of the cassette tape in use 1 6 Winding position of the cassette tap...

Page 10: ...adroom in its drive torque Housing load increasing factors Temperature environment low tempera ture etc mechanism wear or failure 3 The sensor switch for detecting the end of ejection are not functioning normally 4 The loading motor drive voltage is lower than specified or power is not supplied to the motor MDA 5 When the user attempted to eject a cassette a foreign object or perhaps the user s ha...

Page 11: ...y EMG occurrence 04 Moving to the adjacent position in the LOAD direction 06 Moving to the adjacent position in the UNLOAD direction 08 Cassette ejection being executed 0A Cassette insertion being executed 0C Tape being loaded 0E Tape being unloaded 10 Mode transition to STOP with pinch roller compression ON 12 Mode transition to STOP with pinch roller compression OFF 14 Mode transition to STOP wi...

Page 12: ... few times during mode transition and the identification count is variable depending on the cassette tape type If an EMG occurs in the middle of identification the cassette tape type may not be able to be identified If other value than those listed in the above ta ble is displayed the cassette tape type is not identified 7 Cassette tape type 2 Winding area Display Cassette Tape Type 2 00 Cassette ...

Page 13: ...QUENCY RESPONSE 22 CAP_REV L OUT CAPSTAN MOTOR REVERSE CONTROL FWD H REV L 23 D FF OUT ROTATION DETECTION SIGNAL FOR DRUM MOTOR TIMING CONTROL SIGNAL FOR REC 24 V PULSE OUT V PULSE ADDITION TIMING CONTROL 25 RESET RESET TERMINAL RESET ON L 26 A FF OUT AUDIO FF OUTPUT 27 N REC_ST H OUT NORMAL AUDIO SOUND RECORDING START 28 S CASSETTE IN DETECTION SIGNAL FOR SVHS CASSETTE SVHS H 29 SLOW_PULSE OUT RE...

Page 14: ...TL AMP CIRCUIT 73 AVCC SYSTEM POWER 74 CTL_ IN OUT CTL SIGNAL 75 CTL_ IN OUT CTL SIGNAL 76 CTL_AMP_OUT OUT CTL PULSE OUTPUT 77 LOCK L IN TUNING PLL LOCK DETECT L 78 BS_ANT KILLER_OUT NC 79 START_SENSOR IN START SENSOR 80 FULLE ON H 3 58NTSC H GR_ON H OUT FULL ERASE HEAD ON H NC NC 81 REC_SAFETY IN REC SAFETY SWITCH DETECT SW ON L 82 COMPU_OUT WIDE_DET OUT A V COMPULINK OUTPUT NC 83 VIDEO_ENV IN AU...

Page 15: ...l failures If you cannot remove the cassette tape which is loaded be cause of any electrical failure manually remove it by taking the following steps 1 Unplug the power cable and remove the top cover bracket and front panel assembly See 1 3 DISASSEM BLY ASSEMBLY METHOD 2 Unload the cassette by manually turning the loading mo tor of the mechanism assembly toward the front In do ing so hold the tape...

Page 16: ...ig 2 1 3 3 Take the spring of the pinch roller arm assembly off the hook of the press lever assembly and detach it from the tape See Fig 2 1 4 4 In the same way as in the electrical failure instructions in 2 1 3 4 remove the top guide 5 Raise the cassette tape cover By keeping it in that posi tion draw out the cassette tape case from the cassette holder and take out the tape 6 By hanging the pinch...

Page 17: ...assembly Head base Audio control head Loading motor Guide pole guard Pinch roller arm assembly Press lever assembly Lid guide Guide arm assembly Reel disk take up side Sub brake assembly take up side Main brake assembly take up side Idler arm assembly Idler lever Main brake assembly supply side Reel disk supply side Rec safety lever Tension brake assembly Adjust pin Tension arm assembly Pole base ...

Page 18: ...er assembly Clutch unit Take up lever Take up head Control bracket1 Tension arm bearing B1 B22 B3 B5 B6 B7 B8 B9 B10 B12 B15 Rotary encoder guide B16 B17 B18 Brake lever B19 B20 B21 B14 B11 B4 B2 Direct gear B13 Link lever Guide rail Roller cam assembly L2 L1 Opener guide Door opener Drive gear Cassette housing bracket Limit gear Worm gear Belt loading motor Loading motor R2 R3 R5 R4 R1 Fig 2 1 7 ...

Page 19: ...2 2 3 Cassette holder assembly T 6 2 2 3 Drive gear T 4 2 2 3 Drive arm T 8 2 2 4 Pinch roller arm assembly T 1 2 2 5 Guide arm assembly T 1 2 2 5 Press lever assembly T 3 2 2 6 Audio control head T 1 2 2 7 Loading motor T 1 2 2 8 Capstan motor T B 1 2 2 9 UV catcher2 T 1 2 2 9 Polebaseassembly take upside T B 2 2 2 9 Pole base assembly supply side T B 2 2 2 10 Rotary encoder B 1 2 2 11 Clutch uni...

Page 20: ...pes of oil or grease to be used Type Name Serial No Symbols on the dis assembly diagrams Grease Maltemp SH P KYODO SH P AA Oil Cosmohydro HV56 COSMO HV56 BB Table 2 1 2 Grease and oil used for the unit 4 Suggested servicing schedule for main components The following table indicates the suggested period for such service measures as cleaning lubrication and replacement In practice the indicated peri...

Page 21: ...enders the mechanism assem bling mode operational Make sure that the control plate is located in alignment with the mark E See Fig 2 2 1 2 2 3 Cassette Holder Assembly 1 How to remove 1 Remove the guide rail and roller cam assembly See Fig 2 2 2 3 lugs on the guide rail and one lug on the roller cam assembly Fig 2 2 1 Worm gear Guide hole Control cam Chassis hole Control plate Mark E Fig 2 2 3 2 R...

Page 22: ...de of the cassette holder lift the cassette holder assembly so that the three legs on the left side are all released Then pull the legs A and B on the right side out of the rail and also pull up the leg C See Fig 2 2 5 and Fig 2 2 6 Fig 2 2 4 Fig 2 2 6 Cassette holder assembly Lock lever L Drive arm Upright Leg Legs Cassette holder assembly A B C Cassette holder assembly Fig 2 2 7 A B 1 2 Hole Hol...

Page 23: ... See Fig 2 2 9 6 Slide the whole cassette holder assembly toward the front to bring it to the eject end position 7 Install the limit gear so that the notch on the outer cir cumference of the limit gear is brought into alignment with the guide hole on the main deck See Fig 2 2 10 8 Install so that the notch on the periphery of the relay gear is aligned with the notch of the main deck and that hole ...

Page 24: ...emove the spring and expand the lug of the lid guide in the arrow indicated direction Then remove the guide arm assembly by pulling it up 2 Remove the press lever assembly by pulling it up See Fig 2 2 12 Tension spring Press lever assembly Guide arm assembly Lug Lid guide Head base Screws A Audio control head Compression springs Head base Audio control head board assembly Audio control head Screws...

Page 25: ... the rotational direction the capstan motor current may be unstable dur ing operation in high or low temperatures This may result in greater Wow Flutter and occasionally in power break down because of current over load Install the capstan mo tor while following the procedure given below The capstan motor is centrally located when the unit is shipped from the factory 1 Provisionally tighten the thr...

Page 26: ...upply side by removing the screw B NOTE After reinstalling the Pole base assembly and the UV catcher2 be sure to perform compatibility ad justment 2 2 10 Rotary Encoder 1 How to remove 1 Remove the screw A and remove the rotary encoder by pulling it up See Fig 2 2 20 Fig 2 2 20 Rotary encoder Front side Screw A Rotary encoder Back side Positioning pin of the rotary encoder Guide marks Fig 2 2 19 S...

Page 27: ...and catch it from the both sides with the assembly See Fig 2 2 24 Fig 2 2 25 Slit washer Belt Clutch unit 2 2 11 Clutch Unit 1 Remove the belt wound around the capstan motor and the clutch unit 2 Remove the slit washer and remove the clutch unit Slit washers Link lever Locking section of the control plate 2 2 13 Link Lever 1 How to remove 1 Remove the two slit washers 2 Remove the link lever by li...

Page 28: ... the rotary encoder guide Mark E 2 2 14 Cassette Gear Control Cam and Worm Gear 1 How to remove 1 Remove the control cam by lifting it 2 Open the two lugs of the cassette gear outward and pull the latter off 3 Remove the belt wound around the worm gear and the loading motor 4 Open the lug of the lid guide outward and remove the worm gear Fig 2 2 28 Fig 2 2 27 Worm gear Control cam Main deck guide ...

Page 29: ...Press fit Section B Hole B Section C Tension arm assembly shaft Section D Section D Section A Hole A 2 How to install Phase matching 1 Adjust the position of the idler arm assembly pin as indi cated in Fig 2 2 30 to the left of center of the R section 2 Bring the guide hole of the take up lever into alignment with the hole at the control plate guide and fix the posi tion by inserting a 1 5 mm hexa...

Page 30: ...r take up side Projection B 2 2 17 Take up Lever Take up Head and Control Plate Guide 1 Remove the spring of the take up lever from the main deck 2 Remove the lug A of the take up lever from the main deck and pull out the take up lever and the take up head together 3 Remove the screw A 4 Align the idler arm assembly pin in the center of the R section of the control plate guide remove the control p...

Page 31: ...e up side and Main Brake Assembly supply side 1 How to remove 1 Move the main brake assembly take up side in the ar row indicated direction and remove the reel disk take up side 2 Remove the spring attached to the main brake assembly 3 Remove the lug A of the main brake assembly take up side and pull out the lug B after bringing it into align ment with the main deck notch 4 Remove the lugs C D and...

Page 32: ...emove the stator assembly 2 Remove the two screws B and remove the rotor as sembly Note When installing the rotor assembly note that a normal picture cannot be obtained without ensur ing the phase matching as mentioned below 3 Match the phases of the upper drum assembly and the rotor assembly as indicated in Fig 2 2 43 4 Place the upper drum assembly hole a over the rotor assembly holes b with thr...

Page 33: ...er drum assembly Washer Lower drum assembly Shaft 1 5 mm hexagonal wrench Loosen Collar assembly Upper drum assembly Coil parts Lower drum assembly 3 Install the cap to the upper drum assembly 4 Position the collar assembly as indicated in Fig 2 2 46 while controlling its up down movement 6 After installation gently turn the upper drum assembly with your hand to make sure that it turns normally Th...

Page 34: ...the channel buttons simultaneously to enter the manual tracking mode This also brings tracking to the center centre 4 Make sure that there is no significant level drop of the V PB FM waveform caused by the tracking operation with its generally parallel and linear variation ensured Per form the following adjustments when required See Fig 2 3 1 5 Reduce the V PB FM waveform while pressing the chan n...

Page 35: ...azimuth Signal A Alignment tape MHP Mode B PB Equipment C Oscilloscope Measuring point D1 AUDIO OUT terminal D2 TP4001 CTL P Main board External trigger E TP111 D FF Main board Adjustment part F A C head Mechanism assembly Specified value G Maximum waveform 2 3 3 Checking Adjustment of the Audio Control Head Phase X Value Signal A1 Alignment tape MHP A2 Alignment tape MHP L Mode B PB Equipment C O...

Page 36: ... the eject mode perform adjustment for the audio control head phase X value again Signal A Alignment tape MHP L Mode B PB Auto adjust Equipment C Oscilloscope Measuring point D TP106 PB FM Main board External trigger E TP111 D FF Main board Adjustment part F Jig RCU Code 50 Specified value G STOP mode Maximum V PB FM waveform Adjustment tool H Jig RCU PTU94023B 2 3 5 Checking Adjustment of the Ten...

Page 37: ...304 2 320 4 335 IN FF REW OUT PLAY Direct gear Change lever 2 ON HALF REV HALF FF REW OFF Tension arm ON CONTACT OFF Main brake S ON CONTACT OFF Main brake T ON OFF Sub brake S ON OFF Sub brake T ON OFF OFF ON Capstan brake ON OFF Rec safety switch Operation mode ON PLAY ON REV CONTACT OFF C INS Pinch roller SUPPLY CENTER TAKE UP Idler position READY RESET Take up lever ON OFF Guide arm Timer REC ...

Page 38: ...al Color colour bar pattern Fig 3 1 4a Jig RCU INITIAL MODE DATA CODE CUSTOM CODE 43 A CODE 53 B CODE Data transmitting method Depress the 3 button after the data code is set Jig RCU PTU94023B 3 1 4 Switch settings and standard precautions The SW settings of the VCR and the standard precautions for the electrical adjustments are as follows When using the Jig RCU set its custom code to match the cu...

Page 39: ... VCR to the Auto adjust mode by transmitting the code F from the Jig RCU When the VCR enters the stop mode the adjustment is completed 6 If the VCR enters the eject mode repeat steps 1 to 5 again 7 Play back the alignment tape A2 again confirm that the switching point is the specified value G Fig 3 2 1a Switching point V sync Switching point 7 5 0 5H V rate 3 2 2 Slow tracking preset Signal A1 Ext...

Page 40: ... by transmitting the code F1 from the Jig RCU again When the EVR mode is released the adjusted data is memorized Fig 3 3 2a EE Y level H rate 1 00 0 05 Vp p Y level 3 3 3 REC color colour level Signal A1 Alignment tape MH 1H A2 Ext input A3 Color bar signal NTSC Mode B1 S VHS B2 PB B3 REC SP EP PB Equipment C Oscilloscope Measuring point D1 TP106 PB FM D2 PB color output of the LPF External trigge...

Page 41: ... Record the signal A2 in the S VHS SP mode and play back the recorded signal 3 Press the channel buttons simultaneously to enter the manual tracking mode This also brings tracking to the center centre 4 Set the VCR to the EVR mode by transmitting the code F1 from the Jig RCU 5 Set the EVR address to F2 by pressing the button of the digit key remote controller 6 Set the 100 kHz marker level of the ...

Page 42: ...he EVR mode of the VCR by transmitting the code F1 from the Jig RCU again When the EVR mode is released the adjusted data is memorized 7 Disconnect the short wire between the short point D2 and the GND Ground 3 4 AUDIO CIRCUIT Notes This adjustment should be done after the REC color colour level adjustment for the video circuit has been completed GND Ground should be taken from the Tuner shield ca...

Page 43: ...CU again When the EVR mode is released the adjusted data is memorized 7 Disconnect the short wire between the short point D2 and the GND Ground 3 5 6 SAP VCO Signal A RF signal Audio No signal Mode B Tuner EE Equipment C Oscilloscope Measuring point D IC1501 pin 26 Demod board EVR mode F1 Jig RCU Code 57 EVR address F2 A 22 Press remote controller 2 key twice Specified value G Minimum level Adjust...

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