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Extended Diagnostic Codes
Service Code Number
Mode
Comments
50 and 51
Compressors
Diagnostic codes 50 and 51 are used to turn on the
compressors. Code 50 turns on the front compressor
(Fresh Food section) and 51 turns on the rear compressor
(Freezer section). Line voltage is sent to the compressor
inverters on K101 pins 4-6 (white to black) for the
front compressor and 7-8 (white to black) for the rear
compressor. The board will run the individual compressor
for thirty seconds. Condenser fans do not run in this test.
When the main board activates a compressor it sends the inverter a turn on signal from the K108
connector. K108 pins 7-8 (brown to blue) should read 5 VDC (125 Hz) for the front compressor and pins 5-6
(brown to blue) 5 VDC (125 Hz) for the rear compressor. In normal (non-diagnostic mode) the control board
will delay the compressor on signal for 5 minutes for system equalization.
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