Hitachi CM721FET Service Manual
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Hitachi CM721FET Service Manual

Hitachi CM721FET 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 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
SERVICE MANUAL
MANUEL D'ENTRETIEN
WARTUNGSHANDBUCH
MONITOR
December 2001
No. 0410
CM721FET
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.
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  • Page 1 No. 0410 CM721FET SERVICE MANUAL MANUEL D'ENTRETIEN WARTUNGSHANDBUCH CAUTION: Before servicing this chassis, it is important that the service technician read the “Safety Precautions” and “Product Safety Notices” in this service manual. Data contained within this Service manual is subject to alteration for improvement.
  • 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 .....................5 A. D ........................5 ISPLAY B. P ......................5 ICTURE OSITION C. L ..........................5 INEARITY D. G )..............5 EOMETRY ISTORTION ALL PRESET MODES E. A .....................5 LIGNMENT ROCEDURE F. W (9300° ..6 HITE ALANCE DJUSTMENT AS MAJOR TEMPERATURE OW LIGHT ADJUST G.

  • Page 6: Display Alignment

    1. DISPLAY ALIGNMENT A. Display Size All preset mode listings in Table 1. shall be within the following limitations: H. WIDTH: 350 ± 4 mm V. HEIGHT : 260 ± 4 mm B. Picture Position All preset mode listings in Table 1 shall be within the following limitations: H.

  • Page 7: White Balance Adjustment (9300°As Major Temperature) Low Light Adjust

    F. White Balance Adjustment (9300°as major temperature) Low light adjust 9300° 6500° 5000° x = 0.283 ± 10 x = 0.313 ± 15 x = 0.324 ± 15 y = 0.297 ± 10 y = 0.329 ± 15 y = 0.342 ± 15 Y = 0.3 ~ 0.6FL Y = 0.3 ~ 0.6FL Y = 0.3 ~ 0.6FL...

  • Page 8: Power Adjustment

    2 (MAX - MIN) X100% MAX + MIN Any : <10% Adjacent : <6% 8. Geometric check : check and make sure geometric meets spec. 9. Get into OSD select EE-USER item, press ENTER till OSD disappear then turn off power, disconnect JP1, turn on power again, make sure all of the alignment parameters has been stored properly, make H-SIZE adjust range can OVER SCAN and -5%, PHASE adjust range >15mm, V-SIZE adjust range can OVER SCAN and -6%, V-CENTRE adjust range >20mm and make sure TILT adjust works properly.
  • Page 9 J-8. Power Saving Function Check The power source is 230Vac input When the sync signal is removed, the monitor should enter suspend-mode and then off-mode. When power saving, the power consumption of monitor should be less than: suspend mode 8w off-mode The monitor recovering time from suspend-mode or off-mode to on-mode should be less than 5 seconds.
  • Page 10 -- 9 -...

  • Page 11: Controls And Connectors Layout

    2. CONTROLS AND CONNECTORS LAYOUT A. Main PCB -- 10 -...

  • Page 12: Crt/B

    B. CRT/B C. Pin Assignment C-1. Connect Function VR501 : H-CENTRE VR P701 : TILT CONN JP1: PRESET CONN P902 : DEGAUSSING COIL CONN P703 : X-RAY TEST PAD P302 P303 P301 HFLB Vout DSUB9 DDC-SCL EEP-SCL R-IN DDC-SDA EEP-SCL 6.3V H-OUT B-IN...

  • Page 13: Circuit Description

    3. CIRCUIT DESCRIPTION A. Power Supply The F900 power supply is a universal switching mode power supply. It consists of an off-line flyback converter and a Boost converter. The output voltage and current rating are +7.5V / 0.81A, +15.3V / 0.84A, +44V /0.2A, +76V / 0.2A, and B +202V / 0.4A.

  • Page 14: Power Supply Circuit

    C. Power Supply Circuit C-1 RECTIFIER AND FILTER CIRCUIT The 90Vac 260Vac input line voltage is rectified by DB901, and smoothed by C906 via the PFC circuit to provide DC operating voltage for the circuit. C-2 FLYBACK AND PWM CIRCUIT When power is initially applied to the circuit, C909 charges through R903 and Q901.

  • Page 15: Tda4855/4858 Autosysnc Deflection Controller

    C-8 PFC CIRCUIT The PFC CKT is combined with U991A, D901A, T901A..., it is an active type, called” Booster Follower” circuit. The feedback points of U991A is not only connected to C906, but also the AC line-in voltage of C901A which the voltage waveform shape is same as the line-in voltage.
  • Page 16 Pinning SYMBOL DESCRIPTION horizontal flyback input HFLB XRAY X-ray protection input B+ control OTA output BSENS B+ control comparator input B+ control OTA input BDRV B+ control driver output HDRV horizontal driver output GNDP ground (power ground) positive supply voltage FOCUS H- focus parabola output EWDRV...

  • Page 17: Igure (4) (5)

    E. Horizontal Processor H sync go through TDA4855 internal separation circuit to the first comparator for HOR. Phase ADJ and then to stage output. A HOR. Drive pulse from pin 7 and input H-sync limit is setting by R431, R432 and C415. E-1.

  • Page 18: Horizontal Drive

    G. Horizontal Drive The drive pulse output from pin 7 of U401 (TDA 4855) through a buffer (Q416/ Q417) and drive stage (Q503, T501), drives the HOR. Output transistor (Q504). G-1. CS Circuit CS control is multiple type the SW1/ SW2/ SW3/ SW5 of U1 to control Q512/ Q520/ Q514/Q515 CS transistor switch Ref.

  • Page 19: Troubleshooting

    4. TROUBLESHOOTING Start Check and repair EMI Filter Check and Q901-Q902 fuse open R932,R963, DB901-DB904 Check and repair Q903 U903 Q903 VDS D982, M907, M911, D912 Waveform normal? Is 7.5V Check Q902 D926 C937 In spec U904 U908 VR901 Q909 Is B+voltage Check Q902 Q921 D924 U902A Correct?

  • Page 20: Monitor Check Flow Chart

    A. Monitor Check Flow Chart A-1. No raster -19-...
  • Page 21 A-2. No Picture -20-...
  • Page 22 A-3. No vertical deflection (raster become a horizontal line) -- 21 -...

  • Page 23: Appendix A: Schematic Diagrams & Pcb Assemblies

    APPENDIX A: SCHEMATIC DIAGRAMS & PCB ASSEMBLIES -- 22 -...
  • Page 24 BEAD EEP-SCL 4.7k 6.3V BEAD CLAMP V-SYNC TO Q952 C H-SYNC BEAD BEAD RN1203 TO U401 PIN3 HITACHI (EUROPE) LTD 220P 220P Title SCHEMATIC, DEF & POWER VA-916/ 7.5VS SWITCH BOARD VR-916 .01U R100 .01U 100V Sheet 1 of 3...
  • Page 25 C434 R442 1/4W 1/4W 270K 2SD667 1/4W 1/4W 1/4W .01U 4.7K HITACHI (EUROPE) LTD BLANCE R481 Title SCHEMATIC, DEF & POWER VA-916/ PARALLEL SWITCH BOARD VR-916 CORNER NO NOTES ? W RESISTOR IS 1/8W Sheet 2 of 3 H-PHASE N0 NOTES ? V CAPACITOR IS 50V...
  • Page 26 2SA733 1/4W BEAD 7.5VS VR802 R820 C835 1/2W HITACHI (EUROPE) LTD NO NOTES ? W RESISTOR IS 1/8W SCHEMATIC, DEF & POWER VA-916/ 250V Title SWITCH BOARD VR-916 N0 NOTES ? V CAPACITOR IS 50V Sheet 3 of 3 FOR 456A49-01...
  • Page 27 HZ5C1 C969 R926 FR104 ZD902 4.7U 4N35 R998 SYNC 1/4W HITACHI (EUROPE) LTD. GND5 GND5 Title SCHEMATIC, POWER, VA-916 NO NOTES ? W RESISTOR IS 1/8W Sheet 1 of 1 N0 NOTES ? V CAPACITOR IS 50V FOR X62A49-01 X61A49-01...

  • Page 31: Appendix B: Parts List

    THE UPDATED PARTS LIST FOR THIS MODEL IS AVAILABLE ON ESTA...

  • Page 32: Appendix C: Display Unit Assembly

    APPENDIX C: DISPLAY UNIT ASSEMBLY -- 50 -...
  • Page 34 Monitor Assembly FUNCTION KNOB V99921-1 ABS 94HB WG017 FUNCTION KNOB V99921-1 ABS 94HB MCG18 PCB HOLDER(L) M98021 WG017 ABS PCB HOLDER(L) M98021 WG017 ABS+PC PCB HOLDER(R) M98022 WG017 ABS PCB HOLDER(R) M98022 WG017 ABS+PC RUBBER WASHER M98042 t=5.5-1.6 RUBBER PAD M9904F RUBBER PAD(HEATSINK) M9904G COPPER PAPER CBEZEL H9931-1 LOCKING CABLE TIE 142MM...

  • Page 35: Appendix D: Crt & Yoke Assembly

    APPENDIX D: CRT & YOKE ASSEMBLY CRT&YOKE Assembly CRT & YOKE M46QCK761X123 SAM AC500025600 H-CON SET H999 CRT-GND AROUND W5.6 DC020133320 -- 53 -...
  • Page 37 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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