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Hitachi CM821FET Service Manual

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SERVICE MANUAL
CAUTION:
Before servicing this chassis, it is important that the service technician read the "Safety
Precautions" and "Product Safety Notices" in this service manual.
ATTENTION:
Avant d'effectuer l'entretien du châassis, le technicien doit lire les «Précautions de sécurité»
et les «Notices de sécurité du produit» présentés dans le présent manuel.
VORSICHT:
Vor Öffnen des Gehäuses hat der Service-Ingenieur die „Sicherheitshinweise" und „Hinweise
zur Produktsicherheit" in diesem Wartungshandbuch zu lesen.
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
COLOUR MONITOR
DECEMBER 1999
No. 0415
CM821FET
CM823FET
CM827ET
CM828ET
Data
contained
within
this
manual is subject to alteration for
improvement.
Les données fournies dans le présent
manuel d'entretien peuvent faire l'objet
de modifications en vue de perfectionner
le produit.
Die
in
diesem
Wartungshandbuch
enthaltenen Spezifikationen können sich
zwecks Verbesserungen ändern.
Service
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  • Page 1 No. 0415 CM821FET CM823FET CM827ET CM828ET SERVICE MANUAL Data contained within this Service manual is subject to alteration for improvement. Les données fournies dans le présent manuel d’entretien peuvent faire l’objet CAUTION: de modifications en vue de perfectionner le produit.

  • Page 2: Safety Precautions

    FEATURES ESH or Equivalent) Connect (-) to chassis earth and (+) to the CDT anode 1. Flat screen CRT with anti-glare, dynamic focus circuit, button. (See the following connection diagram Fig. 1.) dark glass, and INVAR shadow mask give the NOTE: Turn power switch off without fail before making sharpest focus and highest contrast.

  • Page 3: Product Safety Notice

    Service Manual, may create shock, fire, X-radiation, or other hazards. FIG. 2 CHECKING CIRCUIT USING JIG Productions are issued from time to time. For the latest information, always consult this Service Manual. SPECIFICATIONS CM821FET CM823FET CM827ET CM828ET Model Name Destination...
  • Page 4 CONTROLS Front Cover CRT Surface Power Switch Control Panel Tilt & Swivel Base FIG.3 FRONT VIEW FIG. 3 FRONT VIEW FIG. 4 CONTROL PANEL Signal Cable AC Inlet (D-Sub Mini 15-pin) D-Sub Mini 15-pin FIG. 5 REAR VIEW...

  • Page 5: Signal Timing Chart

    SIGNAL TIMING CHART VESA VESA VESA Signal 640×400 800×600 1024×768 1280×1024 (70Hz) (85Hz) (85Hz) (85Hz) CM821F CM821FET Video Type R/G/B Analog R/G/B Analog R/G/B Analog R/G/B Analog Voltage 0.7 Vp-p 0.7 Vp-p 0.7 Vp-p 0.7 Vp-p Set Up None None...
  • Page 6 VESA VESA Signal Adjustment 1600×1200 1600×1200 640×480 signal (90Hz) (75Hz) (60Hz) CM821F CM821FET Video Type R/G/B Analog R/G/B Analog R/G/B Analog R/G/B Analog Voltage 0.7 Vp-p 0.7 Vp-p 0.7 Vp-p 0.7 Vp-p Set Up None None None None Type H/V Separate...

  • Page 7: Description Of Circuit

    DESCRIPTION OF CIRCUIT 1. Power Supply Circuit This model incorporates a wide range universal power supply utilizing a switching regulator (see block diagram in Fig.6). 1.1 AC input AC input consists of AC inlet, EMI filter (C901 ~C905,C907) and rectifier (D901~D904). Rectifier circuits adapt to full-wave method.
  • Page 8 FIG. 6 BLOCK DIAGRAM FOR POWER SUPPLY CIRCUIT Main power supply Circuit #2 Chopper +85V Chopper +54V +14V Control AC inlet Circuit #1 Degauss Circuit On/Off control Circuit #3 + 6.2V Manual Degauss + 12V Chopper Reg. Control Heater On/Off On/Off control Standby power supply...

  • Page 9: Blanking Circuit

    2. Video Processing Circuit 2.1 Video select circuit (Optional) Two of Video input signals shall be switched at Video selector (I205) controlled by switching signal coming from microprocessor. 2.2 Video Processor The video input signal of 0.7 Vp-p is amplified to approximately 50 Vp-p by the video processing circuit and is fed to the cathode to drive the beam current.
  • Page 10 3. Horizontal Deflection and High Voltage Regulation Circuit 3.1 Horizontal Deflection Circuit The purpose of the horizontal deflection circuit is to cause the CRT electron beam to be scanned horizontally by driving a current through the deflection yoke, synchronized by the H sync pulse. The circuit consists of an AFC circuit, made up of an H phase locked loop and VCO (voltage controlled oscillator), and the deflection output.

  • Page 11: Block Diagram

    FIG. 9 DEFLECTION CONTROL IC BLOCK DIAGRAM 1.2V I701 EWDRV OUT2 EW-Output V-Output Vertical H-Pincushion V-Linearity V-Sync V-sync OUT1 H-Corner V-Linearity Balance Oscillator H-Trapezium Integrator H-Size and AGC clamping Video V-Position blanking Clamping V-Size,VOVSCN V-BLANK FOCUS Focus Horizontal and Vertical HUNLOCK HUNLOCK Protection...

  • Page 12: High Voltage Hold-Down Circuit

    3.2 High Voltage Regulation Circuit The output pulse from Q701 is also fed to the high voltage regulation circuit with the same design of consonant circuit as the horizontal deflection circuit. High voltage of 27.5 kV is obtained by the step-up windings of the flyback transformer to drive the CRT anode.
  • Page 13 4. Vertical Deflection Circuit The purpose of the vertical deflection circuit is to cause the CRT electron beam to be scanned vertically by driving a current through the deflection yoke, synchronised by the V sync pulse. V sync is input to the V oscillator circuit, I701, generating the vertical saw tooth wave.

  • Page 14: Microprocessor Circuit

    5. Microprocessor Circuit The microprocessor circuit consists of the following four detailed circuits as shown in Fig.12. 1. Sync detect circuit 2. Front panel key data Input / Output (I/O) 3. Processing and memory 4. Control output 5.1 Sync detect circuit The sync priority selector (I302) outputs H/V separate or composite sync signal to the sync processor inside the microprocessor (I101).
  • Page 15 FIG. 12 MICROPROCESSOR CIRCUIT...

  • Page 16: Power Save Function

    6. Power Save Function The DJ82 chassis is capable of power savings by sensing of the sync input conditions by the microprocessor. The microprocessor can identify two sync conditions, (1) No detection of H.sync, (2) No detection of V sync. The following table shows the details of the Power save mode.

  • Page 17: Troubleshooting

    TROUBLESHOOTING 1. Raster does not appear Relevant circuit : Power circuit, Horizontal deflection circuit, High voltage limitter circuit Check supply Abnormal Trouble outside the monitor Voltage AC100-200V/ AC 200-240V Normal Q910, I940, D901, D902, D903, D904, Abnormal Abnormal Check F901 Replace F901 C901, C902, C903, C904, C905, C907, C910, C920...
  • Page 18 2. Synvhronization is not obtained Relevant circuit : Sync. input circuit, Microprocessor, Deflection circuit H.SYNC is Check H.Sync. abnormal obtained I101, I104, I201, I302 H.SYNC and V.SYNC of I101 8pin and 9pin Q320, D26Z, D35Z V.Sync. (Change the DJ82 Video V.SYNC is Board or Main Board) normal...
  • Page 19 5. Color does not appear Relevant circuit : Video amplifier circuit Check Abnormal Trouble outside the the input signal. character monitor Normal Check D975, I971 the voltage of 12V (Change the DJ82 Main Board) Normal (12V) Abnormal Abnormal Check the Check Abnormal Check the...
  • Page 20 ADJUSTMENTS 1. Power supply 1.1 Standby power supply voltage adjustment. (1) Turn the switch of the unit off. (2) Place a jumper wire across R943, Q801 (G)-(S), I101(26pin) to GND, I740(13pin) to GND on main-pcb to disable Main power supply voltage. (3) Place resister 3.9kΩ...

  • Page 21: High Voltage Adjustment

    2. Deflection circuit adjustment 2.1 SUB H.SIZE adjustment (1) Turn the switch of the unit off. (2) Connect a Digital multimeter across C771. (3) Turn the switch of the unit on. (4) Receive normal cross hatch pattern of signal 94A. (5) Adjust H.SIZE to maximum and S.Pincushion minimum by the Front Key.

  • Page 22: Brightness Adjustment

    When the value shown below can not low: Change the R827 to R82D. 3.2 White balance adjustment (Color 2) (1) Receive a signal of 112C with a 100×100 mm window pattern. (2) Set Brightness Control to the center (7Fh) and C-Cont to the minimum (00h). (3) Adjust the light output to 80 cd/m (24.6ft-L) at the center of screen by adjusting Sub Contrast Control.

  • Page 23: Focus Adjustment

    4 Focus adjustment (1) Receive signal 94A with a full screen “E” characters. (2) Set user Contrast control to its maximum. (3) Set user Brightness control so that the back ground raster is just diminished. (4) Adjust S-Focus control on the FBT so that focus at the middle points between the center of the screen to its best.

  • Page 24: Wiring Diagram

    WIRING DIAGRAM - 24 -...
  • Page 25 DJ72 BLOCK DIAGRAM 15P-DSUB R . G . B . G A I N C O N T R O L VIDEO INPUT 1 OUT PUT CONTROL C L P H. SYNC V. SYNC BUFFER Sync on G Sep. DDC5V CONT C-CONT SYNC S-BKG...
  • Page 26 Attachment A Page 1 of 5 Procedure to fix the Screen VR on FBT of CM823 Add Copper tape form of 2 input board Add a Grounding Spring for EMI solution . Operation (1) Chassis adjustment should be completed and prepare bond glue (2) Attach the head of glue to bond softly on the right side of Screen VR knob (3) Attach the head of glue to bond softly on the left side of Screen VR knob (4) Attach the head of glue to bond softly on the top of Screen VR knob (Refer to photo 1 )
  • Page 27 Photo 2 Photo 3...
  • Page 28 Photo 4. The grounding spring fix on the Video heat sink MTL and screw it with a tapping screw .
  • Page 29 Photo 5. 1. The 2 GND wires go through a core. (URITE F5B RH 14x15x9) P/N: DC150009800 2. Add a copper finger from CRT cover to the screw of CRT neck. P/N: EEF1154A100.
  • Page 30 ROTATION 100K 1/4W R401 C405 R408 Q401 2SC1213PC +12V R407 R402 E401 Q402 L803 I401 LM358 C401 R405 10mH 2SA673AC C804 R403 0.22U R409 250V D806 ERA32-02TA R406 ST-2SD2012 C406 C404 0.01U Q870 0.01U R871 C80B L80F Q801 2SJ516 R404 100U T801 2.3uH...
  • Page 31 D701 D703 C704 1N4148 1N4148 R704 D702 2.7K D704 R703 1N4148 1/4W 1N4148 3.3K C706 R609 0.01U C707 C604 R501 FOCUS R723 R722 C605 2200P 0.18U R81H 1/4W 0.1U C705 R705 +12V 8200P Q827 "B" 1/4W TDA4856 I701 H.FBP C70X 390P R707 R708...
  • Page 32 +85V FOCUS +12V R534 R516 R525 R530 TRS-2SC4793 R532 D505 1/2W Q504 C515 1SS244 2SC945 Q507 D503 + 50V Q508 2SC945 R517 1N4148 C520 R520 R519 C501 R504 D504 C508 R526 0.033U R502 3.6k 1N4148 1.8k 100K 1/2W C510 2SA733K 100V R531 100V...
  • Page 33 LIMIT R618 1/4W V.BLK R718 1/4W HD74HC157P H.CP R719 1/4W H.BLK C116 R152 C618 SOGCHK 0.01U I104 R155 220P V.IN R133 HZ6B2 R151 V.IN MUTE D1EZ R156 D18Z D1FZ 1/4W HZ6B2 D60Z H.IN D19Z HZ6B2 HZ6B2 R701 R157 I701.15 Q709 R137 *1/4W HZ6B2...
  • Page 34 L98F D98A T940 D901 1N5406 L910 R981 2.3uH ER102 E901 D910 +6.2V 5JLZ47 F901 C910 C941 R918 R941 I981 L91F R984 D902 3300P 0.47U C980 250V 3.3M C920 Q941 KA78R05 2.3uH 500V 1/2W 1000P R916 D911 R91C 220U 2SA1020Y 1N5406 1.5M ER102 250V...
  • Page 35 R289 R251 C2K1 C252 C251 D255 C2F1 C281 C282 1SS270A 220U D21Z 220u 100U Q253 K392 E80C 2SC2412K HZS9A2 C262 D256 R253 Q21B 2SC2735JC I201 C2H1 1SS270A C25R 100U R24B K393 C283 C284 E201 SOCKET R26B R22B C21B C255 0.01U B1(3P) R259 100U...
  • Page 36 R3DR C3CR R3CR D22R *16V 1N4148 INPUT 2 (BP) D26R P201 1N4148 JN3 ,W16 C3CG R3DG R3CG D22G (BP)*16V D26G 1N4148 JN1 ,W15 1N4148 R3DB C3CB D22B R3CB *16V (BP) 1N4148 I205 D26B R3EB 1N4148 E204 C22R 0.01U R3EG C22G R3ER 0.01U D3AZ...
  • Page 37 UL/IEC:T4.0A,250V DEMKO:T4.0AH 250V W278 W289 W290 W292 W368 W260 R92G W378 W369 C917 W282 W287 R915 R92F R914 W377 W283 W281 W288 R91C C92F R92L R913 C92E W168 R92E W337 C918 R92K W269 W370 L91F W275 W165 C906 W291 R91G R91D W153 C913...
  • Page 38 CM821FET Exploded View Showing Final Assembly...
  • Page 39 CM821FET Exploded View Showing Electrical Assembly Details...
  • Page 40 CM821FET Exploded View Showing Mechanical Assembly Details...
  • Page 41 CM823FET Exploded View Showing Final Assembly...
  • Page 42 CM823FET Exploded View Showing Electrical Assembly Details...
  • Page 43 CM823FET Exploded View Showing Mechanical Assembly Details...
  • Page 44 CM827ET Exploded View Showing Final Assembly...
  • Page 45 CM827ET Exploded View Showing Electrical Assembly Details...
  • Page 46 CM827ET Exploded View Showing Mechanical Assembly Details...
  • Page 47 CM828ET Exploded View Showing Final Assembly...
  • Page 48 CM828ET Exploded View Showing Electrical Assembly Details...
  • Page 49 CM828ET Exploded View Showing Mechanical Assembly Details...
  • Page 50 THE UPDATED PARTS LIST FOR THIS MODEL IS AVAILABLE ON ESTA...
  • Page 51 Fax: +46 (0) 8 562 711 13 Tel: +39 02 38073415 Servizio Clienti Email: [email protected] Fax: +39 02 48786381/2 Email: [email protected] HITACHI EUROPE S.A.S HITACHI EUROPE LTD (Norway) AB Lyon Office STRANDVEIEN 18 B.P. 45, 69671 BRON CEDEX 1366 Lysaker FRANCE...

This manual is also suitable for:

Cm823fetCm827etCm828et

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