Carrier 42KCR009713 - Operation lamp flashes and Timer lamp on.

Service manual
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10.7 Operation lamp off and Timer lamp flashes
Operation lamp off and Timer lamp flashes
The voltage of power supply is too low (less than 187V).
No
Indoor PCB is defective.
After changing the main control board, check if the failure realease.
Power supply fault.
No
Outdoor unit fault (such
as the compressor).
10.8 Operation lamp on and Timer lamp flashes
EEROM error, indoor PCB is defective.
10.9 Operation lamp flashes, Timer lamp flashes .
This is alarm signal when the main chip can’t detect over-zero signal. When such failure occurs, the main control
board must have fault.