Door will not open fully or stops mid‑travel; opener shows E4

Safety first: Disconnect power before removing opener covers. Use a stable ladder when working near the opener rail.

• Check for physical stops: Inspect the door path for stops, bolts, or brackets that might be limiting travel. Ensure the top section is not hitting the opener rail or header.
• Reprogram up limit: Using the Skylink control panel, press and hold the UP LIMIT or SET button until the indicator flashes. Use the UP/DOWN buttons to move the door to the fully open position (without hitting the stops), then press SET to save.
• Inspect drive system: With power disconnected, check the chain/belt tension and the trolley carriage. Look for stripped teeth on the drive sprocket or belt, or a cracked trolley.
• Check travel module: Some Skylink models use a travel encoder or magnetic sensor along the rail. Ensure the sensor is firmly mounted and the magnet/encoder strip is intact and aligned.
• Replace worn parts: If the trolley slips or the sprocket teeth are worn, replace the Skylink trolley carriage or Skylink drive sprocket kit as appropriate.