Opener will not respond to wall control or remotes; lights flash eight times; sometimes wall control LED is off or flickering.

Safety first: Unplug the opener before working on low-voltage terminals. Use a non-metallic tool when loosening or tightening terminal screws.

• Inspect wall control: Remove the wall control from the wall. Check for crushed wires behind the control or signs of moisture damage.
• Check wiring at opener: At the opener head, locate the wall control terminals (often marked R and W or similar). Ensure wires are not frayed and screws are tight.
• Bypass test: Disconnect the wall control wires at the opener. Momentarily short the wall control terminals with a small jumper wire. If the opener runs, the wiring or wall control is faulty.
• Test wiring continuity: With wires disconnected at both ends, use a multimeter to check continuity of each conductor. Replace any cable with high resistance or open readings.
• Replace wall control: If wiring tests good but the 8-flash error persists when the wall control is connected, install a new Craftsman-compatible wall control console.
• Reconnect and test: Reconnect wires with correct polarity, restore power, and verify that the wall control LED is solid and the opener responds normally.