Mitsubishi Electric JT-SB116JH2-S-NA Handbook page 14

Troubles without error display
Symptom
Warm air does not blow.
The hand dryer operates
by itself.
The hand dryer does not
stop operation.
Air speed switch does not
change the air volume.
The hand dryer makes
abnormal noises.
Air blow is weak.
Cause
Heater switch Check that the heater switch is turned ON.
(Heater lamp lights with the heater switch ON.)
Connector dis- Check if the connectors TAB3 and TAB4 on the power circuit board
connection for the are disconnected.
heater
Blown thermal Measure the resistance between the connectors TAB3 and TAB4
fuse of the heater on the power circuit board.
If the fuse is blown, the resistance will be ∞ Ω.
In this case, replace the heater (PTC) and the power circuit board.
Malfunction of Check that approx. 120 V AC is output at both ends of the connec-
the power circuit tors TAB3 and TAB4 on the power circuit board. If it is not output,
board replace the power circuit board.
*Note: Approx. 120 V AC is output during operation, and it is not
Heater malfunc- If no error is found after checking the above, replace the heater
tion (PTC).
Connector dis- Check if the following connectors are disconnected.
connection for the 1 Sensor circuit board (JT-30S3R) connector CN12
sensors 2 Sensor circuit board (JT-30S2R) (2 locations) connectors CN15
3 Light receiving circuit board connector CN11
4 Control circuit board connectors CN7 and CN8
Malfunction of Visually check the sensor circuit boards for a defect such as a
the sensor cir- crack, corrosion, or a cold solder joint.
cuit boards (JT- If the error persists after replacing the control circuit board in the
30S1/2/3R) next procedure, replace the damaged sensor circuit boards.
Malfunction of If no error is found after checking the above, replace the control
the control circuit circuit board.
board
Connector discon- Check if the connector CN21 on the control circuit board, CN4 on
nection the power circuit board, or CN30 or CN31 on the filter circuit board
is disconnected.
Malfunction of If no error is found after checking the above, replace the power
the power circuit circuit board.
board
Sucking of foreign Check for any foreign matter sticking to the blower (assembly)
matter vanes.
Clogged filter Check the filter for clogging with dust, etc.
Incorrect wiring Check if the motor lead wires of the blower (assembly) (red to
TAB7, white to TAB8, black to TAB9) are connected to incorrect
TABs on the power circuit board.
( If they are connected incorrectly, the motor turns in the reverse
direction.)
Malfunction of If no error is found after checking the above, replace the power
the power circuit circuit board.
board
Check Method and Remedy
output during standby.
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