AC (indoor) not turning on?

The main PCB is the central control hub; a failed board prevents any startup sequence from initiating.

Likely causes · most likely first

Main PCB

Moderate DIY Part: $80–$200
Fan Motor

Hard DIY Part: $40–$90

A seized fan motor draws excess current and trips internal protection circuits, preventing the unit from powering on.
Installation Plate

Moderate DIY Part: $20–$60

An improperly seated installation plate can interrupt the low-voltage wiring harness connections to the main board.

See the faulty part in 3D.

Tap a highlighted part to see exactly why it fails, how to verify it's the problem, and how to replace it.