Sanyo DP42840 Service Manual

Also see for DP42840 - 42" Diagonal LCD FULL HDTV 1080p: Owner's manual Service manual

Contents

Sanyo DP42840 Service Manual Manual pdf 5 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 thesub_CPU it is necessary to disconnect the AC cordfor a short time.Internal sub_CPU on main IC 5500 is programmed so theset will go to standby mode when there is circuit failure asdescribed below. (Refer to“Block Diagram Power Lines”.)This unit is equipped with a Power Failure Detector functionincluded in the sub_CPU which checks for an abnormalcondition in the chassis power supplies.If, while the power is on, a failure is caused by any of the fol-lowing that results in a low voltage supply, the sub_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 IC5500 pin D9, through RB5501.)(Normal: High; Failure: Low)If, while the power is off, the power is switched on and anyof these failures remains uncorrected, the sub_CPU willshut off the power within three seconds.D9D5IC5500 (sub_CPU)Power FailPower On1Power BoardMainD1668K8BD1641D6700Audio_Pow12V9V5VD16135V