Saturday, April 20, 2013

SHARP LC-M3700 - LC-M3710 - WIDE LCD MONITOR - INVERTERS - SCHEMATICS - GENERAL FAULT TO ALL MODELS


INVERTER-1
INVERTER-2
INVERTER-3
INVERTER-4
FAULT TO ALL MODELS
SYMPTOM  Dead or stuck in standby.
  • All Sharp LCD TV sets have a Lamp Error detection circuit, which will return the LCD TV to stand-by if a fault is detected, the fault is logged by the lamp error counter which will render the LCD TV inoperative if it the error count reaches 5. 
  • To enable fault finding the lamp error detection circuit is ignored when service mode is activated. Service mode activation is detailed in the relevant service manual.
  • After the fault has been diagnosed and repaired the lamp error counter must be reset to “0” before normal functionality is restored, again this is detailed in the relevant service manual.
CAUSE:   Possible causes of this symptom are:
  1. Inverter circuit failure (switching transistors)
  2. Lamp failure (no or low output)
  3. Poor or loose connectors, fuse holders (lamps or inverter board).
  4. Dry joints (power supply or inverter board).
  5. Trapped or chaffed cables to lamps.
  6. Power feed to lamp inverter circuit.
  7. Fault in error detection circuit.
ACTION:  Repair the unit as necessary and reset the lamp counter.