Sanyo CH0971, CH1271 service manual Checking the Indoor and Outdoor Units, Replace the controller

(2)If the self-diagnostics function fails to operate Check the indoor unit.

Is the fuse blown?

Normal

Replace the controller.

•No indicators illuminate and the indoor fan does not rotate.

•Check the power voltage.

Blown

Replace the circuit board or the fuse.

9-3. Checking the Indoor and Outdoor Units

(1) Checking the indoor unit

No.	Control	Check items (unit operation)
1	Use the remote controller to operate the	• The rated voltage must be present between inter-unit wirings 1 and 2.
	unit in "TEST run" mode. To determine	• Connect a 5 k ohm resistor between inter-unit wirings 2 and 3. When the
	whether the mode is currently in	voltage at both ends is measured, approximately 12 to 15V DC must
	"TEST run" mode, check the 4 indicator	be output and the multimeter pointer must bounce once every 8
	lamps on the unit. If all 4 are blinking,	seconds.
	the current mode is "TEST run."	Or instead of measuring the voltage, you can insert an LED jig and
		check that the LED flickers once every 8 seconds.
If there are no problems with the above, then check the outdoor unit.
For the "Test run" procedure, refer to the Appendix B "Installation Instructions".
(2) Checking the outdoor unit
No.	Control	Check items (unit operation)
1 Apply the rated voltage between outdoor		• The control panel LED (red) must illuminate.
	unit terminals L and N.

2Short-circuit the outdoor unit COM terminal • The compressor, fan motor and 4-way valve must all turn on. to the T-RUN terminal.

If there are no problems with the above, then check the indoor unit.

Using the TEST/T-RUN terminals		TEST/T-RUN terminals
T-RUN : Test run (compressor and fan motor turn ON).
TEST/MV : Compresses time to 1/60th (accelerates
operation by 60 times faster than normal).
	(TEST)/MV		T-RUN	COM

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