Mitsubishi Electronics P500YMF-C Check method and handling, After checking , if these are factors

(2)Trouble and remedy of remote controller (In the case of MA remote controller)

Phenomena				Factors			Check method and handling
1 If pushing the remote		1)	Power supply from transformers is not turned on in		a)	Check the MA remote control terminal
control operation SW			Indoor Unit.			voltage (between A and B).
does not make a			1	The original power supply of Indoor Unit is not		i) In the case of voltage DC8.5- 12V,
sound such as feep				turned on.		the remote controller is defective.
with the crystal			2	The connector (CND. CNT, CN3T) on the		ii) In the case of voltage not available:
display lamp out, and				controller board in the room has come off.		● Check the left described 1) and 3),
no operate is			3	Fuse on the control board in Indoor Unit has melting down.			after checking , if these are factors,
possible.			4	Transformer defects or damage to unit.			then modifications should be
		2)	MA remote controller has been wired incorrectly.				performed.
(An appropriate			1	Break of the MA remote controller line and the		● If there are no factors of the left
display	on the			connection to the terminals has come off.			described 1) and 3), move to b).
remote control is not			2	Short circuit of the MA remote control wiring	b)	Remove the remote control wiring from
on.)			3	Reversed connections of the wiring on remote		the terminal block TB13 for the MA
				controller.		remote control in the indoor unit, and
			4	Incorrect connection of the MA remote control wiring		check voltage between A and B.
				to the transmission line terminal block (TB 5).		i) In the case of voltage DC9-12V
			5	Reversed connections between the MA remote		Check the left described 2) and 4), if
				control wiring in the indoor unit and AC 200V		these are factors, then modifications
				power supply wiring.		should be performed.
			6	Reversed connection between the MA remote		ii) In the case of voltage not available:
				control wiring in the indoor unit and M-NET		● Recheck the left described 1) once
				transmission wiring.			again, if this is a factor, them
		3)	The maximum number of MA remote controllers				modifications should be performed.
			connected to one is unit exceeded (two units).			● If there are no factors in the left
		4)	The wiring length of the MA remote line and the				described 1), check the wiring for the
			used electric wire diameter is out of specifications.				remote display (the relay polarity, etc.)
		5)	The wiring of the remote display output to the			● If there are no factors, replace the
			outdoor unit is short circuited, or the relay is				controller board in the indoor unit.
			connected with reversed polarity.
							In the case of item 1), the
		6)	Defective of the controller board in the room
							LED 1 on the controller
		7) Defects of MA remote control
							board in the unit is off.
2 When turning on the		1)	M-NET transmission power supply from the outdoor unit is not
remote control			supplied.
operation SW, a			1	The original power supply of the outdoor unit is not turned on.
temporary operation			2	Disconnection of connectors on the board of the outdoor unit.
display is indicated,				Main board --- CNS1, CNVCC3
and the display lights				INV board --- CNAC2, CNVCC1, CNL2
out immediately, the			3	Power supply circuit defects of the outdoor unit.
unit stops.				(For detail, refer to Pages 127)
			● INV board defects					In the case of factors 2) and
			● Blown fuse (F1 on INV Board)
								3) Indicated by 7102 error
			● Diode stack destruction
								code on the self-diagnosis
			● Prevention resistance of rush current (R1) damage
								LED of the outdoor unit.
		2)	Transmission line short
		3)	Wiring mistakes of the M-NET transmission line on the side of
			the outdoor unit
			1	Break of transmission line, and removal of terminal block
			2	The room transmission line is wired to the transmission line
				terminal block (TB7) for the central control by mistakes.
		4)	M-NET transmission line break on the side of the room unit
		5) Disconnection off wiring between the M-NET transmission terminal block
			(TB 5) and the room controller board CN2M and pulls off of connectors

Check method and handling

The same	NO
phenomena occurs in all units of
the same refrigerant system?
		Terminal block (TB15)
YES		voltage check for the
		transmission line of the
Self-diagnosis LED		indoor unit
check		NO
	Check for 4) item
		19 ~ 12V?
		YES

7120 error display?	YES	Check for 2) and 3) of	Check for 5) item
		factors

NO	YES
Modify the defect	Factors available?
Check for 1) item	NO
Modify the defect	Defects in the indoor
	unit controller board or
	MA remote control

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