Laser Engraving and Cutting

• What should I do if the Snapmaker Original laser is weak or there is no light at all when it is on?
• What should I do if the laser cannot burn the material though I can see the laser beam?
• What should I do if there is no laser coming out from the laser engraving module at my first try?
• What should I do if the Snapmaker Original laser engraving module cannot work anymore?