Remote not working traced to receiver path, not indoor PCB

What we found

Remote-control faults need the signal path checked first. We split the checks into remote, receiver, and board to narrow the cause.

• Unit power was present and the issue was command response only
• Remote signal was being sent but not received
• Fault was traced to the signal receiver path

The problem was in the IR receiver path, where the unit picks up remote commands. The main indoor board was not at fault. The symptom looked like a board problem because the unit ignored all commands, but the receiver was the issue.

What we did

The main board is fine. The fault is in the IR receiver path, which is a much smaller component. Repairing the receiver restores full remote control without touching the main board.

After the signal receiver path was corrected, the remote worked normally again. No board replacement was needed.

What we learned

How to tell an IR receiver fault from a main board failure.

• The IR receiver is a small, separate component that picks up remote signals. It can fail independently of the main board, and replacing it is a much smaller repair.
• Splitting the fault check into remote, receiver, and board — in that order — prevents the main board from being replaced unnecessarily when the real issue is earlier in the signal chain.
• The main indoor PCB handles cooling, fan speed, and compressor control — if the unit still runs in any mode, the board is likely intact. Command failure alone points to the signal receiver path, not the board.