Mitsubishi Electric CAHV-P500YB-HPB Service Handbook page 142

[ IX Troubleshooting ]
(1) Judgment methods and possible failure mode
Malfunction
mode
Microcomputer
driver circuit fail-
ure
LEV mechanism
is locked
Disconnected or
short-circuited
LEV motor coil
Faulty wire con-
nections in the
connector or
faulty contact
HWE15070
Judgment method
Disconnect the control board connector and connect
the check LED as shown in the figure below.
resistance
LED
Pulse signal is output for 17 seconds when the main
power is turned on.
If there is any LED that remains unlit or remains lit,
there is a problem with the drive circuit.
If the LEV is locked, the drive motor runs idle, and
makes a small clicking sound.
When the valve makes a closing and opening sound,
the valve has a problem.
Measure resistance between the coils (red - white, red
-orange, brown - yellow, brown - blue) using a tester.
They are normal if resistance is 150ohm
Measure resistance between the coils (red - white, red
-orange, brown - yellow, brown - blue) using a tester.
They are normal if resistance is 46ohm
1. Check for loose pins on the connector and check
the colors of the lead wires visually
2. Disconnect the control board's connector and
conduct a continuity check using a tester.
6
5
4
resistance:0.25W 1kΩ
3 LED:15VDC 20mA more
2
1
10%.
3%.
- 135 -
Remedy
When the drive circuit has a
problem, replace the control
board.
Replace the LEV.
Replace the LEV coils.
Replace the LEV coils.
Check the continuity at the
points where an error occurs.
GB