MEDION Service Manual 17-inch Color Monitor B1770NSL/T (MD1772LB)
Service Manual Versions and Revision No. 1. Ve rsion Re le ase Dat e Re vision 1.0 Aug. 11, 2000 Ori gi nal r el ease Copyright Trademarks Copyright 2000 LiteOn Technology Corp. LiteOn is a registered trademark of LiteOn Technology Corp. All Rights Reserved This manual may not, in whole or in part, be copied, photocopied, reproduced, translated, or converted to any electronic or machine readable form without prior written permission of LiteOn Technology Corp.
MEDION MD 1772LB (B1770NSL/T) Table of Contents 1. Precautions.........................................................................................................2 2. Product Specifications .......................................................................................5 3 Control Location and Functions ...................................................................... 10 4. Operation Theory..............................................................................................
MEDION 1 MD 1772LB (B1770NSL/T) Precautions Follow these safety and servicing precautions to prevent damage and to protect against potential hazards such as electrical shock and X-rays. 1-1 Safety Precautions 1-1-1 Warnings 1. For safety purpose, do not attempt to modify the circuit board, and always disconnect the AC power before performing servicing on the monitor. 2. Operation of the monitor outside its cabinet or with the cover removed involves the risk of shock hazard.
MEDION MD 1772LB (B1770NSL/T) 1-1-3 Product Safety Notices Many electrical and mechanical parts in this chassis have special safety-related characteristics which are often not evident from visual inspection, the protection afforded by them may not be obtained by replacing them with components rated for higher voltage, wattage, etc. Before replacing any of these components, consult the Recommended Spare Parts List given at the end of this manual.
MEDION MD 1772LB (B1770NSL/T) d) Plug monitor power cord to the Hi Pot tester terminals. e) Turn on tester and watch the indicator or beeper. f) If the indicator lamp lighten, or beeper beeps, the test fails. 1-4 Ground Continuity Test 1. Test Equipment AC low ohm tester TOS-6100 or equivalent approved equipment. Note : The test equipment must be calibrated in regular period. 2. Test Setup a) Test duration : 3 seconds b) Set current limit at 25 A c) The grounding resistance must be less than 0.1 ohm. 3.
MEDION 2 MD 1772LB (B1770NSL/T) Product Specifications 2-1 Specifications Pi c tur e Tub e 1 7 - i nc h ( 1 5 . 8 - i nc h Vi s ua l i ma ge a r e a) , s l o te d ma s k, 9 0 d e gr e e s d e fl e c ti o n, d o t typ e b l a ck ma tr i x, me d i um s ho r t p e r s i s te nc e p ho s p ho r, d a r k ti nt, no n- gl a r e / a nti - s ta ti c s c r ee n, 0 .
MEDION MD 1772LB (B1770NSL/T) 2-2 Signal Cable Pin Connections Table 2-1. Signal Cable Pin Assignment Pin Signal Pin Signal 1 Red vi de o 9** PC 2 Gr een vi deo 10 Di gi tal Gr ound 3 Bl ue vi de o 11 Gr ound 4 Gr ound 12 SDA 5* NC 13 H- Sync 6 Red gr ound 14 V- Sync / VCL 7 Gr een gr ound 15 SCL 8 Bl ue gr ound Note: * This pin is used for selftest detection. Connect this pin to ground at the PC end. ** For PC99 : this pin will provide +5V from PC side.
MEDION MD 1772LB (B1770NSL/T) 2-3 Timing Chart This section describes the timings that the computer industry recognizes as standard for computer-generated video signals. Table 2-2. Timing Chart M ode 1 2 3 4 5 6 7 8 9 10 11 12 13 14 H. Dots 720 640 640 800 640 640 800 1024 800 1024 1024 800 1280 1024 V. Dots 400 480 480 600 480 480 600 768 600 768 768 600 1024 768 H-fre q (kHz) 31.47 31.47 35 37.88 37.5 43.3 46.8 48.36 53.67 56.48 60.02 62.966 64.
MEDION MD 1772LB (B1770NSL/T) 2-4 Display Power Management Signal (DPMS) Note: These power-saving states exceed the Environmental Protection Agency (EPA) Energy Star requirements and the Video Electronics Standard Association (VESA) for Display Power Management Signal (DPMS) . Table 2-3.
MEDION MD 1772LB (B1770NSL/T) 2-6-2 TCO 95 Version (Optional) The TCO 95 scheme is for international and environmental labelling of personal computers. The labelling scheme was developed as a joint effort by the TCO (The Swedish Confederation of Professional Employ ees), Naturskyddsforeningen (The Swedish Society for Nature Conservation) and NUTEK (The National Board for Industry and Technical Development in Sweden).
MEDION 3 MD 1772LB (B1770NSL/T) Control Location and Functions (1) (2) (3) (4) (5) (6) (1) (2) (3) (4) (5) (6) Function Key Decrease Key Increase Key Select Key Power LED Power ON/OFF 3-1 Front Panel 3-2 Front Panel Keys Functions 1. Function Key: Display the main menu, and exit the adjustment screen and save adjustments. 2. Decrease Key: Scroll across main menu, highlighting control to be adjusted. Decrease value of selected control. Toggle between Contrast and Brightness adjustment screens. 3.
MEDION 4 MD 1772LB (B1770NSL/T) Operation Theory This is a fully digital controlled multi-sync color monitor that is compliant with DDC1/2B Plug and Play VESA standard and offers the following main features. 4-1 Main Features 1. Simplified design with minimum components. 2.
MEDION MD 1772LB (B1770NSL/T) 4-3-1 Horizontal Section 1. The oscillator is driven by the currents in R467 and R468. The minimum oscillator frequency is determined by R467 and the maximum frequency is determined by R468. 2. Horizontal sync goes into pin 15 through R494. And horizontal flyback pulse goes into pin 1 through R479 and bypass filter C446 from Emitter of Q403 and C406, C407, C461, R407, D432, R404, R402 for AFC loop. 3.
MEDION MD 1772LB (B1770NSL/T) 4-3-7 Contrast Section 1. Contrast is controlled by I701 through I2C bus to I501 (TDA4886) directly. 2. Beam current is detected through T402 (FBT) pin 7, C432, Q418, VR402, R453, Q419 and detected voltage feeding into R510, R509, R507,C523 to control I501 pin 24 voltage. When I501 pin 24 voltage drops below 5V, the ABL function will happen.
MEDION MD 1772LB (B1770NSL/T) 2. Regulation The DC O/P voltage is proportional to the auxiliary voltage, so I801 pin 2 senses the feedback voltage from the divider R802, R823, VR801 and R821 to compare with the built-in 2.5 volts reference voltage for error amplifier operation. Finally pin 6 can modulate the different duty cycle by VR801 setting to achieve regulation purpose. 4-4-6 Synchronization 1.
MEDION MD 1772LB (B1770NSL/T) 5. Under override condition, “CHECK SIGNAL” will show up on the screen. 4-6 OSD (On Screen Display) Circuit 1. The I502 HTV021-02 is OSD IC. The OSD signals are worked by positive vertical pulse from I701 pin 32 that goes through R521 to I502 pin 10, and positive horizontal pulse from HFLB1 through R513 to I502 pin 5. CPU I701 pin 27, 28 (I 2C bus) transfers information to I502 pin 7, 8. 2. The OSD R. G.
MEDION 5 MD 1772LB (B1770NSL/T) Alignments and Adjustments This section of the service manual explains how to make permanent adjustments to the monitor settings. 5-1 General Adjustments 5-1-1 Adjustment Conditions a) Power Supply Apply AC 115 V or 220 V b) Warm-up Time The monitor must be powered on for 15 minutes before starting any alignment, but requires 30 minutes of warm-up time for convergence adjustment. c) Signal Input 1. Video: RGB Analog, 0.7 Vp-p, positive 2.
MEDION MD 1772LB (B1770NSL/T) 5-2 Alignment Procedures 5-2-1 High Voltage Adjustment CONDITION Display image : Crosshatch pattern PROCEDURE Connect DC meter to TP5 and adjust VR401 to obtain a DC voltage of -130 ± 0.2 V DC. 5-2-2 Screen and White Balance Adjustment CONDITION Press 1 and 2 buttons simultaneously when switching the power “On”. Bias VRs : VR961, VR901, VR931 Display image : No video PROCEDURE 1 Raster color setting 1-a. Set Brightness through OSD menu to -40 V at G1 and 560 V at G2.
MEDION MD 1772LB (B1770NSL/T) 4-b. Adjust VR 402 to Y=29.5FL ± 1FL. 4-c. Check the white balance at 5FL and 28FL. 4-d. Repeat all the procedures in 5-2-2 section until the best white balance is obtained 5-2-3 Focus Adjustment CONDITION Display image : “e” character pattern PROCEDURE 1. Set Brightness to cutoff and Contrast to maximum. 2. Adjust top VR at T402 (static focus VR) to make vertical line clear. 3. Adjust center VR at T402 (dynamic focus VR) to make horizontal line clear. 4.
MEDION MD 1772LB (B1770NSL/T) Figure 4-1. Convergence Magnets on the CRT 1 11 + P CRT FRONT 9 87654 10 3 2 1) Setup Bolt 2) Bow Magnet 3) Band 4) 2-Pole Magnet 5) Spacer 9) Holder 6) 4-Pole Magnet 10) Band 7) Spacer 11) Tabs 8) 6-Pole Magnet 3. Rotate the individual rings of 4-pole convergence magnets by changing the spacing between the 2 tabs to converge the vertical red and blue lines at the center of the screen. 4.
MEDION MD 1772LB (B1770NSL/T) 5-2-6 Degaussing Degaussing is required when poor color impurity appears on the screen. This monitor uses an automatic degaussing circuit that is activated when the power is on. The automatic degaussing will be fully functional again after the monitor has been in operation for 20 minutes. The degaussing effect is confined to the picture tube since the coils are mounted at the back of the tube.
MEDION 6 MD 1772LB (B1770NSL/T) Troubleshooting 6-1 No Raster No Raster Measure voltage of B+ at T402 pin 3 on PWB-MAIN 0V Short Circuit at load? No Normal (68 V, 31.5 kHz) High (75 V or more) Check voltage of cathode, heater, Grid 1, Grid 2, etc.
MEDION MD 1772LB (B1770NSL/T) 6-2 OSD Abnormal OSD Abnormal Check I502 missing? Yes Put on I502 No Check R530, R532, R531 OK? No Replace them No Replace it Yes Check JP806, L504, L505 OK? Yes Replace I502 Page 22
MEDION 6-3 MD 1772LB (B1770NSL/T) Function Key Abnormal Function Key Abnormal Check I701 and I703 missing? Yes Put on I701, I703 No Power ON/OFF again and check X701, oscillator OK? No Replace X701 No Replace I703 or do ATE again Yes Replace I701 Yes Check R735, C710 Yes Check I703 EEPROM content OK? Yes Replace I701 and check uP OK? No Check pin 5 of I701 is 5V? No Replace I804 Page 23
MEDION MD 1772LB (B1770NSL/T) 6-4 No Vertical Scan (Raster is one horizontal line) No Vertical Scan Check I301 voltage of pin 3 is 12V, pin 7 is 48V? No Ckeck or replace I301.
MEDION MD 1772LB (B1770NSL/T) 6-5 Out of Horizontal Synchronization Out of Horizontal Synchronization Horizontal sync present at pin 15 of I401 No Ckeck or replace the signal cable or I701 No Check or replace the signal cable or I701 No Ckeck signal cable & vertical sync input & I701 Yes Check I401 pin 8 H output frequency Yes Check Q401, T401, Q402, R4A6, D402, R403, D402 6-6 Out of Vertical Synchronization Out of Vertical Synchronization Vertical sync present at pin 14 of I401 Yes Check I
MEDION MD 1772LB (B1770NSL/T) 6-7 R.G.B. Video Amplifier Abnormal RGB Video AMP Abnormal Check waveform at I501 pin 16, 19 and 22 No Check or replace the signal cable or I501 No Check Q964, Q904, Q934 Yes Check Q963, Q903, Q933 collector voltage and wave form Yes Video signal present at the pin of the CRT R.G.B.
MEDION 7 MD 1772LB (B1770NSL/T) Recommended Parts List Note: 1. 2. The components identified by “ the same parts specified. “ mark are critical for X-ray safety. Replace these with only There is only OTP IC at the model beginning (FPR stage or before). When it put in mass production and there must be Mask coming out. If you have spart parts need, please use BOM to get the last release part number and related information. No. Location Part Number Description 1 C407 6326315446 MPP uF 0.
MEDION No. MD 1772LB (B1770NSL/T) Location Part Number Description 22 R804 6201100012 THERMISTOR 10 OHM 3A P=5 TKS 23 R818 6220327852 FS OHM 0.27 1W J HOR 24 T401 6135000801 XFRMR HOR DRIVE THD-1008A EI19 25 T402 6133070120 FBT TFB-7012 FEA867 SAMPO 26 T403 6111155174 COIL CHOKE 150 uH 27 T801 6138001601 LINE FILTER TLF-1016A 16mHET28 28 T802 6131060820 XFRMER PWR TPW-1070 EI40 29 X701 6449000719 CRYSTAL 8MHz TOP8.
MEDION G R911, R912, Q903, Q904, Q902, Q905 Q901 R BUFFER & DC RESTORE R941, R942, Q933, Q934, Q932, Q935 Q931 G BUFFER & DC RESTORE R G B HEATER G1 G2 FOCUS 1 Q961 B BUFFER & DC RESTORE FOCUS 2 VIDEO AMP R971, R972, Q963, Q964, Q962, Q965 4V GND B P901 GND Block Diagram GND R GND GND 130V 12V 80V 6.
MEDION LITE-ON TECHNOLOGY CORP. 5 F, No. 16, Sec. 4, Nanking E. Road, Taipei, Taiwan Tel: 886-2-25706999 Fax: 886-2-25706888 URL:// www.liteontc.com.
