Sanyo DP50749 Service Manual

Also see for DP50749 - 50" Plasma TV: Setup guide Basic operation guide Owner's manual Service manual

Sanyo DP50749 Service Manual Manual pdf 9 page image

– 5 –POWER FAILURE CIRCUITCheck the following if the unit is turned off by the powerfailure detector.1. Disconnect the AC power cord (120V AC line) for a shorttime.2. Connect a DC Voltmeter to the circuits shown below.3. Press the Power key and check for the proper voltagesupplies.4. If any of these voltages is low, the power failure detec-tor should turn the unit off within three seconds.5. Check all circuits shown below.Note: If power failure is detected 3 times in 15 minutes,the set will enter the standby mode and cannot beswitched On.To reset the operating programs of theCPU it is necessary to disconnect the AC cord for ashort time.CPU (IC800) is programmed so the set will go to standbymode when there is circuit failure as described below.(Refer to“Block Diagram Power Lines”.)This unit is equipped with a Power Failure Detector functionincluded in the CPU which checks for an abnormal condi-tion in the chassis power supplies.If, while the power is on, a failure is caused by any of thefollowing that results in a low voltage supply, the CPU willturn the unit off in 1.5 seconds to prevent further damage:• Failure within the power supply circuits.• A short circuit in the load side from the supply.Power Failure: Detected voltage failure for circuit.(Connected to IC800 pin 48 and pin 23.)(Normal: High; Failure: Low)If, while the power is off, the power is switched on and anyof these failures remains uncorrected, the CPU will shut offthe power within three seconds.4818IC800 (SUB-CPU)1,25,624,223Power FailPower OnPower Fail1(LVDS)Power BoardMainD1660D1683K8BD1651D1674IC16809VQ16515VIC167015VK8BLVDS_POWD16333,6D1632 IC16303.3V