Samsung AM072FXVAFH series Service Manual page 180

Troubleshooting
Refrigerant leakage error
AM038/048/055KXWD
Outdoor unit display
∙ Before starting : Before compressor starting after system halt 2 minutes (High & low pressure sensor Open / Short error occurs
Judgment Method and1kg/ ㎠ or less)
∙ When start : When the high pressure sensor value(cooling 3.1kg/ ㎠ , heating 2.2kg/ ㎠ ) is detection continuously for 3 seconds
∙ Refrigerant leakage and shortage
Cause of problem
∙ Disconnection or breakdown of high & low pressure sensor
1. Pressure sensor Open / Short error determination method
1) Identifies from when power is supplied or 2 minutes after RESET, and only when set is stopped.
2) An Open / Short error will occur if the input voltage standard range of 0.5V ~ 4.95V is exceeded.
2. How to check
Did the pressure sensor connector breakaway
from the PCB?
Is there refrigerant inside the set?
(Please check by connecting the manifold gauge to
the service valve)
Out of the PCB pressure sensor terminals, is there
voltage between pins (3 and 4) 5V?
Replace pressure sensor
4-84
(cont.)
✳✳
(Refrigerant leakage judgment before starting)
(When start, refrigerant leakage judgment)
Yes
Yes
Yes
No
Restart after connecting the connector to the PCB
No
Charge the refrigerant after vacuum
No
The mark is the 1st pin on the PCB.
Replace PCB
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