Troubleshooting - Mitsubishi Electric JT-SB216JSH2-W-NE Handbook

9. Troubleshooting

Work precautions
• When servicing, be sure to recreate the malfunction two or three times before starting repairs.
• When servicing, always take care to keep proper footing.
• Before starting the service, always unplug the power cord from the outlet, or turn off the earth leakage
breaker when no power cord plug is provided. Sufficient care must be taken to avoid electric shock or injury.
• Make sure to connect the power supply wires correctly.
• When removing the circuit board, always hold it at both ends and remove carefully so as not to apply force
to the surface mounted parts.
• When removing the circuit board, be careful of the metal edges on the board.
• When removing or inserting the connectors for the circuit board, hold the entire housing section. Never pull
on the lead wires.
• When circuit board failure is considered to be a cause, check closely for any broken section on the copper
foil patterns, burning or discoloration of parts.
• After replacing a circuit board, make sure to restore the same settings as before the replacement.
(1) Table of the safety devices
Overcurrent protection
Protection against an excessive tempera-
ture rise of the heater parts
Protection against an excessive tempera-
ture rise of the blower parts
Motor lock protection
Purpose
Current fuse
Thermal fuse
Thermal fuse
• Current detection circuit
( Detects abnormal current caused by the motor lock, and stops
the power to the motor.)
• Current fuse
─ 12 ─
Device