Gree GWH12MB-K3DNE3G Service Manual page 54

Service Manual
13.Flow chart for outdoor communitcation circuit detecting:
(1) Test the voltage between N point of wiring board and communication cable with universal meter. The voltage shall be
variable. Otherwise, it might be malfunction of mainboard of indoor unit, or malfunction of mainboard of outdoor unit, or
wrong wire connection of indoor and outdoor unit. Please ensure that there is no malfunction of mainboard of indoor unit, or
wrong wire connection of indoor and outdoor unit. After removing the malfunction of indoor unit, remove the malfunction of
outdoor unit.
(2) Test the voltage of pin 1 and pin 2 of U132 with universal meter (voltage of both sides of R135). The voltage should be
variable. (Test 10) Test the voltage of pin 3 and pin 4 of U132 with universal meter (voltage of both sides of R1312). The
voltage should be variable. (Test 15) Otherwise, there is malfunction of mainboard of outdoor unit.
(3) Test the voltage of pin 3 and pin 4 of U131 with universal meter (voltage of both sides of R134). The voltage should
be variable. (test 11) Test the voltage of pin 1 and pin 2 of U132 with universal meter (voltage of both sides of C134). The
voltage should be variable. (test 12) Otherwise, there is malfunction of mainboard of outdoor unit.
(4) Test the voltage between pin 1 of R135 (white) and pin 1 of U4. The voltage should be variable. Test voltage between
pin1 of R131 (white) and pin 1 of U4 with universal meter. The voltage should be variable. Otherwise, there is malfunction of
mainboard of outdoor unit.
Installation and Maintenance
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