Hitachi CM625ET Service Manual
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Hitachi CM625ET Service Manual

Hitachi CM625ET Service Manual

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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
„Sicherheitshinweise" und „Hinweise zur Produktsicherheit" in diesem
Wartungshandbuch zu lesen.
SERVICE MANUAL
MANUEL D'ENTRETIEN
WARTUNGSHANDBUCH
Gehäuses
hat
der
October 2000
Service-Ingenieur
die
No. 0503
CM625ET
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
modifications
en
perfectionner le produit.
Die
in
Wartungshandbuch
enthaltenen
Spezifikationen
können
sich
Verbesserungen ändern.
de
vue
de
diesem
zwecks
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Summary of Contents for Hitachi CM625ET

  • Page 1 No. 0503 CM625ET SERVICE MANUAL MANUEL D’ENTRETIEN WARTUNGSHANDBUCH CAUTION: Before servicing this chassis, it is important that the service technician Data contained within this read the “Safety Precautions” and “Product Safety Notices” in this Service manual is subject to service manual.
  • Page 2 ALL PRODUCTS CE MARK Before any service is performed on the chassis an 1. HITACHI products may contain the CE mark on isolation transformer should be inserted between the the rating plate indicating that the product power line and the product.
  • Page 3 POUR TOUS LES PRODUITS LABEL CE Avant d’effectuer une intervention d’entretien sur le 1. Les produits HITACHI peuvent avoir reçu le label châssis, vous devez insérer un transformateur d’isolement CE qui figure sur la plaque signalétique pour indiquer entre la ligne d’alimentation électrique et le produit.
  • Page 4 Hochspannung sollte immer auf den festgelegten Der Gebrauch von Ersatzteilen, die nicht dieselben Wert des Gehäuses beschränkt bleiben und nicht Sicherheitsmerkmale haben wie die empfohlenen mehr. Betrieb bei höherer Spannung kann zum HITACHI Ersatzteile, wie sie in der Ersatzteilliste Versagen Bildröhre oder hoher aufgeführt sind, kann zu elektrischem Schlag, Feuer,...

  • Page 5: Table Of Contents

    1. DISPLAY ALIGNMENT ............... 1 A. Times & Display Size ..................1 B. Picture Position ....................1 C. Linearity ......................1 D. Geometry Distortion (All Preset Mode)............1 E. Alignment Procedure ..................2 ...... 2 White Balance Adjustment (9300°as major temperature) Low light G.
  • Page 6 6. DEFLECTION ................16 A. SYNC Processor.................... 16 B. Hor. Processor & Vert. Pre- AMP..............16 C. Vertical Output ....................16 D. Horizontal Driver Circuit ................. 16 E. Horizontal Output Stage................. 16 F. Flyback Transformer ..................16 7. VIDEO AMP. CIRCUIT..............20 A.
  • Page 7 WARNING 1) This product contains components which are critical for X-radiation safety. Read the Service manual carefully for proper replacement. Maximum 2nd anode voltage use high impedance meter, connect (-) to chassis, use a high voltage lead from (+) to 2nd anode. 2) Critical Components are marked with the symbol of in the material list.

  • Page 8: Display Alignment

    1 DISPLAY ALIGNMENT A. Times & Display Size For all presetting mode listing in table 2 shall be within the limitation: H. WIDTH 310 ± 3 mm V. HEIGHT 233 ± 3 mm The external control range of the data area, shall be as follows; Max.

  • Page 9: Alignment Procedure

    E. Alignment Procedure E-1. Brightness Adjust: 1) Adjust the VR980, have the +198VS By 198V± 0.2V (The voltage of the C949) in TIMING 1. 2) Check below items. C944 : 16 ± 1V The voltage of C947 : 75 ± 2V C946 : -12.5 ±...

  • Page 10: Convergence Adjustment

    H. Convergence Adjustment Input R+B and R+G signals, make sure convergence within specified. A zone = 0.3MM., B zone 0.4MM. (X) < 0.4MM, (Y) < 0.4MM, and x <0.45MM. NOTE : 1. A area = 233mm (circle) 2. B area = 310 x 233 mm If not, readjust 4P and 6P on the deflection yoke to bet mis-convergence within specification.

  • Page 11: Power Adjustment

    J. Power Adjustment J-1. Adjust the VR901, have the +198Vs be 198 ± 0.2v ( the voltage of the C949 ) in timing J-2. Check below items the voltage C944 : 16 ± 1v C947 : 75 ± 2v C946 : -12.5 ± 1.5v C940 : 9.8 ±...
  • Page 12 TABLE2: PRESETING MODES Mode H Pixes Fd(MHz) Fh (KHz) Th(us) Td(us) Tb(us) Tp(us) Tf(us) Factor L Lines Polar(H/V) Fv(Hz) Tv(ms) Td(ms) Tb(ms) Tp(ms) Tf(ms D:dot: D:display B: backporch P:plus F: front 25.175 31.469 31.778 25.422 1.907 3.813 0.636 70.087 14.268 11.122 1.875 0.064...
  • Page 13 Fig. 1 Fig. 2 Fig. 3...

  • Page 15: Video Pcb

    B. Video PCB...

  • Page 16: Pin Assignment

    C. Pin Assignment C-1. Connect Function P701 : TILT, H Convergence, V Convergence CONN JP1: PRESET CONN P902 : DEGAUSSING COIL CONN P730 : X-RAY TEST PAD P302 P303 P301 V-out DSUB9 D-SUB POWER EEP-SDA R-IN DDC-SCL ON/OFF H-BLK EEP-SCL DDC-SDA LED2 CLAMP...

  • Page 18: Power Supply Portion

    4 Operation Theorem A. INTRODUCTION D796 is a 17” multisync color monitor. The horizontal frequency range is from 30khz to 96khz, and the refresh rate is from 50hz to 160hz. The circuit includes four major parts, the power supply circuit, the deflection circuit, the video circuit and the digital control circuit. Fig. 1 is the function block diagram.

  • Page 20: Power Supply

    5 POWER SUPPLY A. RECTIFIER AND FILTER CKT The 90Vac-260Vac input line voltage is rectified by D901-D904, and smoothed by C906 to provide DC operating voltage for the circuit. B. FLYBACK AND PWM CKT When power is initially applied to the circuit, C909 charges through R903, Q905. When the voltage across C909 reaches a level of 16V, U901 is enabled, turning on Q902 and turning off Q905 to complete start-up action.

  • Page 21: Power Factor Correction Ckt (Optional)

    H. POWER FACTOR CORRECTION CKT (OPTIONAL) PFC CKT is inserted between the rectifier bridge (D901-D904) and C906, U991A (MC33260) drives the switching MOSFET, Q901A, is working as a free running, discontinuous voltage mode. This control way named “ follower boost” Connecting three resistors (R906A, R907A &...

  • Page 23: Deflection

    6 DEFLECTION A. SYNC PROCESSOR H-sync & V-sync or input to U1 (u-P), then u-P output the H-out & V-out to U401 (TDA4856). B. HOR. PROCESSOR & VERT. PRE-AMP Fig.2 is the block diagram of IC TDA4856. Hor. processor The H-out that come from u-P will input to the pin 15 of U401, it will be compared with the oscillator sawtooth voltage by the PLL1 (pin 26) phase detector, After that, it will be compared again with the flyback pulse (pin 1) by the PLL2.

  • Page 24: Flyback Transformer

    E. HORIZONTAL OUTPUT STAGE C541 C511 C520 C521 C519 C525 → Cs=C511+C541+C520+C521C+C519+C525 30~32.9k 33~35.9k 36~39.9k 40~44.9k 45~50.9k 51~54.9k 55~57.9k 58~61.9k 62~65.9k 66~70.9k 71~83.9k →Cs=C511+C541 84~above F. FLYBACK TRANSFORMER In the primary of F.B.T, there is about 700Vpp in the LC resonant interval, It convert to the secondary of F.B.T to produce about 25KV for CRT anode voltage.
  • Page 26 Vertical Deflection Booster TDA4863; TDA4863A Fig. 3...

  • Page 27: Video Amp. Circuit

    7 VIDEO AMP. CIRCUIT A. VIDEO PRE. AMP. The video pre-amp IC is U301 (M52743). The input signal is 0.7Vpp, then pre-amp IC U301 amplify the video signal to 4~5Vpp. The WHITE BALANCE and CONTRAST can be adjusted internal by I C bus.
  • Page 28 LM2435 Simplified Schematic Diagram (One Channel) Fig. 5...

  • Page 29: Troubleshooting

    8 TROUBLESHOOTING A. Power Supply Check...

  • Page 30: Monitor Check Flow Chart

    B. Monitor Check Flow Chart...

  • Page 31: Appendix A: Pcb Assembly

    APPENDIX: A PCB ASSEMBLY...
  • Page 32 THE UPDATED PARTS LIST FOR THIS MODEL IS AVAILABLE ON ESTA...

  • Page 33: Appendix B: Display Unit Assembly

    APPENDIX B: DISPLAY UNIT ASSEMBLY...
  • Page 34 Top Assembly - MD796...
  • Page 35 FOR MECHANICAL...
  • Page 36 For Electrons MPRII (Mitsubishi CRT)
  • Page 37 For Mechanical TCO99...
  • Page 38 For Electrons TCO99 (Mitsubishi CRT) NOTE: ITEM WITHOUT DRAWING...
  • Page 39 CRT & YOKE Assembly - MD796...
  • Page 40 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...

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