An article on howcast.com lists the troubleshooting steps to follow if your automatic garage door refuses to open.
- Check the plug – make sure the cord is plugged in and the power is turned on.
- Make sure it’s not locked – many doors have a lock feature, which may have been inadvertently activated.
- Turn it off and on again – sometimes the sensors need resetting and this will often do the trick.
- Check the batteries – inspect and replace the batteries in your remote if they are flat.
- Reprogram the remote – resetting your remote may fix the problem, if it has become deprogrammed.
- Check the sensor – make sure it is plugged in and clean the ‘eye’, as it may have dust on it.
- Check the chain – a broken or loose chain could cause the problem. If it is broken, you will need to have a new one fitted.
- If all these steps fail to fix the problem, pull the red release cord, so that you can at least open and close the door manually, until a professional repairer can be contacted.