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Daewoo 720D Service Manual

Manual is about: XGA COLOR MONITOR

Summary of 720D

  • Page 1

    Daewoo electronics co., ltd. Http : //svc.Dwe.Co.Kr service manual xga color monitor model : 720d 905d 905ds 905df january, 2001.

  • Page 2: Contents

    Contents safety precautions 1 general safety information 2 servicing precautions 3 technical information 6 general information 7 pin connector 8 cautions for adjustment and repair 8 operation and adjustment 9 alignment procedure 13 troubleshooting hints 15 block diagram 30 pcb layout 31 schematic di...

  • Page 3: Safety Precautions

    1 safety precautions ◆ safety check care should be taken while servicing this analog color display because of the high voltages used in the deflection circuits. These voltages are exposed in such areas as the associated flyback and yoke circuits. ◆ fire & shock hazard • insert an isolation transform...

  • Page 4: General Safety Information

    2 general safety information warning: this product includes critical mechanical and electrical parts which are essential for x ray protection. For continued safety, replace critical components that are indicated in the service manual with exact replacement parts given in the parts list. Operating hi...

  • Page 5: Servicing Precautions

    3 servicing precautions ◆ general servicing precautions 1. Always unplug the ac power cord from the ac power source before: a. Removing or reinstalling any component, circuit board, module, or any other instrument assembly. B. Disconnecting or reconnecting any electrical plug or other electrical con...

  • Page 6

    4 ◆ electrostatically sensitive (es) devices some semiconductor (solid state) devices can be damaged easily by static electricity. Such components are commonly called electrostatically sensitive (es) devices. The typical examples of es devices are integrated circuits, some field-effect transistors, ...

  • Page 7

    5 figure 1. Use soldering iron to pry leads ◆ ic removal/replacement some utilized chassis circuit boards have slotted (oblong) holes through which the ic leads are inserted and then bent flat against the circuit foil. When holes are slotted, the following technique should be used to remove and repl...

  • Page 8: Technical Information

    6 technical information ◆ diode removal/replacement 1. Remove defective diode by clipping its leads as close as possible to diode body. 2. Bend the two remaining leads perpendicularly to the circuit board. 3. Observing diode polarity, wrap each lead out of the new diode around the corresponding lead...

  • Page 9: General Information

    7 general information this color monitor automatically scans all horizontal frequencies from 30khz to 95hz, and all vertical frequencies from 50hz to 160hz. This color monitor adopted the osd (on screen display), it shows the sync polarity and frequency and it provides that easily adjust control. Th...

  • Page 10: Pin Connector

    8 pin connector cautions for adjustment and repair • degaussing is always required when adjusting purity or convergence. • the white balance adjustment has been done by a color analyzer in factroy. The adjustment procedure, described in the service manual is made by a visual check. • allow 20 minute...

  • Page 11: Operation & Adjustment

    9 operation & adjustment control panel • move cursor to the right window on the osd window. • increase the value of any selected function. • move cursor to the left window on the osd window. • decrease the value of any selected function. • launch osd(on-screen display) menu window. • move cursor to ...

  • Page 12

    10 key process osd off menu menu menu menu • when you choose the icon on the osd window, you can exit the osd screen. Hot key brightness contrast.

  • Page 13

    11 adjust the width (horizontal size) and the height (vertical size) of the display. H. Size & v. Size h. Linearity v. Linearity adjust the horizontal linearity. Adjust the vertical linearity. Select language for osd (5 languages). Language adjust the position of the display horizontally(left or rig...

  • Page 14

    12 adjust the parallelogram when the screen is leaning left or right. Adjust the rotation when the screen is tilted left or right. Adjust the pin corner top when the top sides of the screen are bowed. Rotation t. Pin corner parallelogram adjust the trapezoid of the screen by moving the lines inward ...

  • Page 15: Alignment Procedure

    13 ◆ standard adjustment conditions 1. Power source voltage : ac 100 - 240vac, 50/60hz. 2. Aging : take at least 15 minutes warm-up time. 3. Signals. Video : analog 0.7vpp 75 Ω terminal positive polarity synchronizing : composite h+v sync : 1.0vpp ~ 5.0vpp (positive / negative) separate h, v sync : ...

  • Page 16

    14 5. Static convergence adjustment (a) apply a magenta cross hatch pattern on display. (b) adjust the focus from the best over all focus on the display. Also adjust the brightness to the desired condition. (c) vertical red and blue lines are converged by varying the angles between the two tabs of t...

  • Page 17: Troubleshooting Hints

    15 troubleshooting hints 1. No character.

  • Page 18

    16 2. No raster.

  • Page 19

    17 3. A missing color.

  • Page 20

    18 4. Abnormal osd font.

  • Page 21

    19 5. Horizontal output circuit mode scan b+ vga (31.5khz) 43v 43khz 60v 68khz 97v 79khz 112v 91khz 127v.

  • Page 22

    20 6. Unstable picture 6-1. Horizontal.

  • Page 23

    21 6-2. V.Osc/deflection circuit.

  • Page 24

    22 7. Focus.

  • Page 25

    23 7-1. Dynamic focus fv h fvv 720d : 300v 140v 905d : 320v 180v 905ds : 400v 200v 905df : 350v 170v.

  • Page 26

    24 8. Convergence.

  • Page 27

    25 9. Abnormal picture 9-1. Horizontal size * at first, adjust controls in the osd menu mode scan b+ vga 43v 43khz 60v 68khz 97v 79khz 112v 91khz 127v * the b+ are as follows:.

  • Page 28

    26 9-2. Vertical size.

  • Page 29

    27 10. High voltage output circuit Ω ∞.

  • Page 30

    28 11. Power supply unit (p.S.U) replace r025.

  • Page 31

    29.

  • Page 32: Block Diagram

    30 block diagram hvg (philips) video d-sub rgb h/v video pre amp lm1253a(ns) video out amp lm2453(ns) hv drive / control mcu mc68hc908bd48 (motolora) h/v osc processor tda4856 (philips) geometrical compensatio h-driver drive transformer h/v moire cancellation usb-port 1 up stream 4 down stream ac in...

  • Page 33

    31 pcb layout 720d/905d/905s/905df main pcb component side.

  • Page 34

    32 720d/905d/905s/905df main pcb solder side.

  • Page 35

    33 720d/905d/905s/905df crt pcb component side 720d/905d/905s/905df crt pcb solder side.

  • Page 36

    34 905d/905ds control pcb component side 905d/905ds control pcb solder side.

  • Page 37

    35 905df control pcb component side 905df control pcb solder side.

  • Page 38

    36 schematic diagram power or connection section.

  • Page 39

    37 control & vertical section.

  • Page 40

    38 deflection & hige voltage section.

  • Page 41

    39 video section.

  • Page 42

    40 exploded view & mechanical parts list 720d.

  • Page 43

    905d 41.

  • Page 44

    42 905ds.

  • Page 45

    43 905df.

  • Page 46

    44 resistor description example: capacitor description example: fig & part no description index capacitors c102 ccxf1h104z ceramic 50v 0.1µf z c402 ccxb1h331k ceramic 50v 330pf k c105 cmxm 2a224j mylar 100v 0.22µf j allowance c ± 0.25pf d ± 0.5% f ± 1pf j ± 5% k ± 10% p ± 100% ~ 0% z ± 80% ~ – fig &...

  • Page 47: Electrical Parts List

    Loc part-code part-name part-desc note 00020 w3475n731- cord power 3 h05vv-f 3x0.75 1.8 iv 00160 5m20000003 coil tilt tc-17b-1 720d only b002 5pb13857-- coil bead bi3857(axial) b301 5pb13857-- coil bead bi3857(axial) b502 5pb13857-- coil bead bi3857(axial) b801 5pb13857-- coil bead bi3857(axial) b80...

  • Page 48

    46 loc part-code part-name part-desc note c311 cexf1h109v c electro 50v rss 1mf (5x11) tp c313 cexf1h109v c electro 50v rss 1mf (5x11) tp c314 ccxb1h221k c cera 50v b 220pf k (tapping) c315 ccxb1h221k c cera 50v b 220pf k (tapping) c316 ccxf1h104z c cera 50v f 0.1mf z c317 ccxb1h221k c cera 50v b 22...

  • Page 49

    47 loc part-code part-name part-desc note c547 cexf2e330v c electro 250v rss 33mf (13x25) tp c548 cmxl2e473j c mylar meu 250v 0.047mf j(tp) c549 ccxb3a102k c cera 1kv b 1000pf k (tapping) c551 ccxf1h104z c cera 50v f 0.1mf z c552 cmyf2d824j c mylar mpp 200v 0.82mf j c553 ccxf1h104z c cera 50v f 0.1m...

  • Page 50

    48 loc part-code part-name part-desc note c846 cexf1e470v c electro 25v rss 47mf (5x11) tp c847 ccxf1h104z c cera 50v f 0.1mf z c848 cexf2a220v c electro 100v rss 22mf (8*11.5) tp c849 cmxl2a104j c mylar meu 100v 0.1mf j c851 cexf1c101v c electro 16v rss 100mf (6.3x11) tp c852 ccxf1h104z c cera 50v ...

  • Page 51

    49 loc part-code part-name part-desc note d106 d1n4937gp- diode 1n4937gp (tapping) d107 dug2d----- diode ug2d 200v 2a d108 dzn4148--- diode 1n4148 auto 52mm d109 d1n4937gp- diode 1n4937gp (tapping) d111 d1n4937gp- diode 1n4937gp (tapping) d203 dzn4148--- diode 1n4148 auto 52mm d301 dzn4148--- diode ...

  • Page 52

    50 loc part-code part-name part-desc note dz011 ddz4r7bm-- diode zener dz-4.7bm dz101 dgdzj18c-- diode zener gdzj 18c dz201 ddz5r1b--- diode zener dz-5.1b dz202 ddz5r1b--- diode zener dz-5.1b dz203 ddz5r1b--- diode zener dz-5.1b dz204 ddz5r1b--- diode zener dz-5.1b dz316 ddz5r1b--- diode zener dz-5....

  • Page 53

    51 loc part-code part-name part-desc note q011a tspp04n60s fet spp04n60s5 q100 tztc3198y- tr ktc3198y-(1815y) (auto) q104 tztc3207-- tr ktc3207 (auto) q105 tztc3198y- tr ktc3198y-(1815y) (auto) q301 tzsr1006-- tr ksr1006 (auto) q303 tzsr1006-- tr ksr1006 (auto) q304 tztc3198y- tr ktc3198y-(1815y) (a...

  • Page 54

    52 loc part-code part-name part-desc note r022 rd-az471j- r carbon film 1/6 470 ohm j r023 rd-az103j- r carbon film 1/6 10k ohm j r025 rw01z128jn r wire wound 1w 0.12 ohm j non-induct r026 rx05v122j- r cement 5w 1.2k ohm j vertical r027 rd-az563j- r carbon film 1/6 56k ohm j r028 rd-az330j- r carbon...

  • Page 55

    53 loc part-code part-name part-desc note r355 rd-az472j- r carbon film 1/6 4.7k ohm j r361 rd-az393j- r carbon film 1/6 39k ohm j r362 rd-az473j- r carbon film 1/6 47k ohm j r363 rd-4z822j- r carbon film 1/4 8.2k ohm j r364 rd-2z470j- r carbon film 1/2 47 ohm j r365 rd-az101j- r carbon film 1/6 100...

  • Page 56

    54 loc part-code part-name part-desc note r524 rd-az103j- r carbon film 1/6 10k ohm j r525 rs01z129j- r m-oxide film 1w 1.2 ohm j (tapping) r528 rd-az153j- r carbon film 1/6 15k ohm j 905df only r528 rd-az393j- r carbon film 1/6 39k ohm j 720d,905d,905ds only r530 rd-az244j- r carbon film 1/6 240k o...

  • Page 57

    55 loc part-code part-name part-desc note r572 rd-az151j- r carbon film 1/6 150 ohm j r573 rd-az471j- r carbon film 1/6 470 ohm j r574 rd-az471j- r carbon film 1/6 470 ohm j r576 rd-4z304j- r carbon film 1/4 300k ohm j r578 rs01z129j- r m-oxide film 1w 1.2 ohm j (tapping) r579 rd-4z104j- r carbon fi...

  • Page 58

    56 loc part-code part-name part-desc note r832 rd-az330j- r carbon film 1/6 33 ohm j r834 rd-az820j- r carbon film 1/6 82 ohm j r835 rd-2z330j- r carbon film 1/2 33 ohm j r837 rd-az105j- r carbon film 1/6 1m ohm j r851 rd-az750j- r carbon film 1/6 75 ohm j r861 rd-az750j- r carbon film 1/6 75 ohm j ...

  • Page 59

    Daewoo electronics co., ltd 686, ahyeon-dong mapo-gu seoul, korea c.P.O. Box 8003 seoul, korea telex : dwelec k28177-8 cable : "daewooelec" e-mail : djkoo@web.Dwe.Co.Kr tel : 82-2-360-7806 fax : 82-2-360-7877.