Sharp ARM276

Error Code:

Code: H4-21
Description: Sub heater lamp abnormally low temperature detection
The setup temperature (about 25°C: Sim 43-1-1) is not reached within the specified time (about 32sec) from turning on the power ON SW. (When the temperature falls below 140°C in the standby mode.)
Causes: Sub heater thermistor defect Sub heater lamp failure Sub thermostat failure Control PWB failure
Remedy: Check the sub heater lamp blinking with SIM 5-2-2. When the lamp blinks normally: Check the thermistor and the harness. Check the MCU PWB thermistor input circuit. When the lamp does not light: Check for disconnection of the heater lamp and thermostat. Check the interlock switch. Check the power PWB and the MCU PWB lamp control circuit. Clear the display of self-diagnostics with SIM 14.

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