Sanyo LCD-20XR1/AU Service Manual

Contents

This series models adopt built-in power. The power to the main board may be different when the unitadopts different panels or whether the audio amplifier is located on the main board or not. The followingis the detailed power in different cases.Model Audio amplifier Power socketnumber on themainboardDefinition of the pins (as follows, PBIAS refers tobacklight ENABLE, PWM refers to backlightbrightness control signal.)LC-20XR1 AN5277, locates onpower board, Vcc=18VX7028 pin1, 2: +12V 3, 4: GND 5: +3.4V6: GND; 7: PBIAS 8: PWM1. No raster, no picture and no soundWhen the main power is turned on, the unit’s indicator lights up in red (red indicator is controlled by+3.3VSTANDBY), use the remote control or the unit’s STANDBY to lights up the blue indicator.Whether the IR board’sred indicator lights up?Power board’s +3.3Vis abnormalWhether the blueindicator lights upwhen press theSTANDBY button?Confirm the IRsensor and its powe rsupply is normalIndicator damages or blueindicator +9V power isabnormal (check +9V circuit)Whether thebacklight lights up? Whether the voltageof the panel isnormal?8125is abnormal withoutsignal output or the outputsignal is abnormalWhether the backlightpower or PBIAS pin islBacklight boarddamage or protection.Replace the backlight boardWhether thebacklight power orPBIAS pin is normalCheck power circuit or whether the 8125PBIAS signal is normalNYYY YYN YNN18TROUBLESHOOTING CHARTS