If your garage door has stopped while opening, it could be due to a problem with the electrical opener or a mechanical issue with the door itself. In either case, you'll need to identify the problem and fix it before you can get the door working again. If it's an electrical problem, you may be able to fix it by checking the power supply and ensuring that all of the wires are properly connected. If it's a mechanical issue, you may need to adjust the hinges or lubricate moving parts. Always consult your owner's manual if you're not sure how to fix a specific problem.
If the garage door opener suddenly stops working, it is likely that there is something blocking the infrared beam between the remote control and the unit on the garage door. First check to see if anything is in the way, like a leaf or a piece of paper. If that's not the problem, then you may need to clean the sensors on both the opener and remote. To clean them, use a Q-tip and rubbing alcohol. Be sure to wipe in between each sensor and also to clean off any dirt or dust that may have collected on them. If you still have problems after cleaning them, then it's possible that they are no longer aligned properly and will need to be realigned.