AOC LM925 SERVICE MANUAL 19” LCD MONITOR LM925 THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE EFFORT HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE ACCURACY OF THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS RE LIABILITY FOR...
AOC LM925 Revision List Version Date Revision History TPV Model Name Feb-08-06 Initial Release T980KH4HBAA1AP Oct-14-2006 Add TPV Model in item11 T980KA2HLAMGAP...
AOC LM925 2. LCD Monitor Description The LCD MONITOR will contain a main board, a power board, a keypad board and an audio board which house the flat panel control logic, brightness control logic and DDC. The power board will provide AC to DC Inverter voltage to drive the backlight of panel and the main board chips each voltage.
AOC LM925 3. Operating Instructions 3.1 General Instructions Press the power button to turn the monitor on or off. The other control buttons are located at front panel of the monitor. By changing these settings, the picture can be adjusted to your personal preferences.
AOC LM925 3.3 Adjusting The Picture The Description For Control Function: Main Main Menu Sub Menu Sub Menu Adjust Menu Description Reset Value Item Item Icon Range Icon Recall Cool Contrast Contrast from Digital-register. 0-100 Contrast Value Luminance Recall Cool...
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AOC LM925 Model) Do not execute Auto Config, return to main menu. Adjust the horizontal position of H. Position 0-100 the OSD. Adjust the vertical position of the OSD Setup V. Position 0-100 OSD. Adjust the OSD timeout. 10-120 Timeout...
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AOC LM925 REMARK: 1) MCU initialize. 2) Is the EEprom blank? 3) Program the EEprom by default values. 4) Get the PWM value of brightness from EEprom. 5) Is the power key pressed? 6) Clear all global flags. 7) Are the AUTO and SELECT keys pressed? 8) Enter factory mode.
AOC LM925 5.3.2 Inverter/Power Board AC input Bridge Rectifier IC101 Transformer Rectifier diode EMI filter and Filter Start Circuit: R906、 R907 CN902 Feedback Over Voltage Circuit Control IC Protect ON/OFF OSC and MOSFET DC Convert Output Circuit Circuit Lamp Over...
AOC LM925 8. Maintainability 8.1 Equipments And Tools Requirement Voltmeter. Oscilloscope. Pattern Generator. DDC Tool with an IBM Compatible Computer. Alignment Tool. LCD Color Analyzer. Service Manual. User Manual.
AOC LM925 8.2 Trouble Shooting 8.2.1 Main Board No power No power Press power key and look if the picture is normal Please reinsert and make sure the AC of 100-240 is normal Reinsert or check the Adapter/Inverter section Measure U201 PIN2=1.8V U202 PIN2=3.3V...
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AOC LM925 No picture (LED orange) No picture The button if X601 oscillate Replace X601 under control waveform is normal Check reset circuit of Check Correspondent component U601 is normal Measure U201 PIN2=1.8V U202 PIN2=3.3V Replace U601 Replace U201, U202...
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AOC LM925 White screen White screen Measure Q204 base X601 oscillate waveform is normal is high level? Replace X601 Check Q204, Q203 are Check reset circuit of broken or CN503 solder? U601 is normal Check Correspondent Check Correspondent component. component.
AOC LM925 8.2.2 Power/Inverter Board 1) No power Check CN902 pin2, 4 = 12V Check AC line volt 110V or 220V Check AC input Check the voltage of C905(+) Check bridge rectified circuit and F901 circut Check start voltage for the pin3 of IC901...
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AOC LM925 2.) No Backlight Check CN902 pin2, 4 = 12V Check adapter or Main Board Check ON/OFF signal Check Main Board Check U201 pin9=12V Change Q201 or Q202 Check U201 PIN1 have the output of sawtooth wave at short time Change U201 Check D201 (-)/ D202 (-) have the output of square wave at short time.
AOC LM925 8.2.3 Keypad Board OSD is unstable or not working Is Key Pad Board connecting normally? Connect Key Pad Board Replace Button Switch Is Button Switch normally? Replace Key Pad Board Is Key Pad Board normally? Check Main Board...
= 313±20, y = 329 ±20, Y =180 cd/m 3. Into factory mode of AOC LM925 Turn on power, press the MENU button, pull out the power cord, and then plug the power cord. Then the factory OSD will be at the left top of the panel.
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AOC LM925 C. Adjust sRGB color-temperature 1. Switch the chroma-7120 to RGB-Mode (with press “MODE” button) 2. Switch the MEM.channel to Channel 5 (with up or down arrow on chroma 7120) 3. The LCD-indicator on chroma 7120 will show x = 313 ±20, y = 329 ±20, Y = 180 cd/m 4.
AOC LM925 11. BOM List T980KH4HBAA1AP Location Part No. for TPV Description Quantity Unit Q1G 330 10120 SCREW FOR FP/RC AUPC980KHP AUDIO BOARD CBPC980KH4A1P CONVERSION BOARD KEPC980KHP KEY BOARD PWPC1942HSE1P POWER BOARD 15G6093H13 1 MAIN FRAME 34G1276AGD 1B BACK COVER...
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AOC LM925 AM1G1740 12 47 SCREW 34G1277 GM B BASE E089A 89G404C18N YH POWER CORD E089B 89G1738LAB D1 SIGNAL CABLE 705L980KB34069 33G4695 1 C CLAMP 33G4711 GM L KEY PAD 33G4712 1 C POWER LENS 34G1273 GM B STAND 34G1275 GD 2B...