Mitsubishi Electric PQRY-P200YEM-A Service Handbook page 103

Phenomena
3 When the remote 1) Power supply from the transformer is not available to the control board of BC controller.
control SW is turned
on, the indication
goes off after
approximately 20- 30
seconds, and indoor
unit stops.
Check method and handling
Check the BC controller
power terminal block
voltage
220 ~ 240V?
YES
Fuse check on the
board
Fuse blown off
NO
Connector removal
checks
(CN03, CN12, CNTR)
Removed?
NO
Check for resistance
value of transformer
Within spec.?
YES
BC controller
Defects for the
control board
1 As for transformer checks, It is subject to the failure judgment method of main parts in 4.5.
1 The original power supply of the BC controller is not turned on.
2 Removal of connectors (CN12, CN38, CNTR) on the control board of the BC controller.
3 Fuse on the control board of the BC controller is blown.
4 Transformer defects of the BC controller and a malfunction.
5 Defects on the control board of the BC controller
Verify the power
NO
supply wiring original
power supply.
220 ~ 240V circuit
YES
short and ground
checks
YES
Connector connection
defects
Check for factors of
transformer cut
NO
Earth route on the board
Earth route of sensor
and LEV
Factors
Power supply
reapplying
1
Modify the defective
places
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