Carrier 40MPHA Service Manual page 30

E2 (Zero crossing detection error diagnosis and solution)
Description: When PCB does not receive zero crossing signal feedback for 4 minutes or the zero crossing signal time interval is abnormal.
Recommended parts to prepare:
• Connection wires
• PCB
Troubleshooting and repair:
Check the connections and
power supply.
Is it normal?
Indoor main PCB is defective.
Replace the indoor main PCB.
30
NO
YES
Specifications subject to change without notice.
Correct the connections. Power on the
unit when the power supply is good.
40MPHA-03SM