Sanyo H3ELM Service Manual

Also see for HT32744: Owner's manual Quick and easy setup

Contents

— 18 —SERVICE HINTSPOWER FAILURE DETECTORThis unit is equipped with a Power Failure Detector function included in the CPU which checks for an abnormal condition inthe chassis power supplies, including the power supply derived from the Horizontal Output Transformer.If, while the power is on, a failure is caused by any of the following that results in a low voltage supply, the CPU will turn theunit 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.• Stoppage of the Horizontal Output Oscillator caused by the X-Radiation protection Hold-Down Circuit.If, while the power is off, the power is switched on and any of these failures remains uncorrected, the CPU will shut off thepower within three seconds.Check the following if the unit is turned off by the power failure detector.1. Disconnect the AC power cord (120V AC line) for at least 10 seconds.2. Connect a DC Voltmeter to the circuits shown below.3. Press the Power key and check for the proper voltage supplies.4. If any of these voltages is low, the power failure detector should turn the unit off within three seconds.5. Check all circuits shown above.Note: This unit is equipped with a Power Surge Protection feature included in the CPU. If power failure occurs three timeswithin 15 minutes, the CPU will automatically stop functioning to help prevent secondary damage. (TV will not turn onby pressing the power key.) To reset the operating programs within the CPU, disconnect the AC power cord for at least10 seconds.Block Diagram (Power Fail Lines)14IC801 (CPU)D663MainMainDAFR655R6565VTV 6.5V14VTVIC662D6625VIP IC663D66121VD664 R655R6569VTVD66531VTVIC66114VD23029V IC23036.5VD23035V IC2304D654 D6593.3VDM14VDMIC652D676 D6532.5VDM IC65312V14VIC43045VIC4305VideoFrontK23VBD (19)K8VBD (19)K1901 (5)K9FRB (5)14VD12819V IC1281D622 D621D50821VT601D5103.3V2.5V IC7103IC501D7103 R71125VIC7102AVK10G (6)KG (6)K4D (2)K6PDD (2) P/DQ7101D7102D7101TJ7 15D652 D63135V 21D649 D623 D656-15V 16Q642(Switching)(V Out)D486 D481D4365D4366200VT40243D429 D482D4289Hold Down(Circuit)VerticalOutput(FBT)R487R488IC2501 12(CRT Driver) Hold Down(Circuit) K5B (8)k23VDA (15) K6PDB (8)Q851/Q825IC651D509K8VDA (15)K43B (9) K4DF (9)39Power ON/OFFQ1611RL601(Main Relay)