From my 30 plus years in the laser and instrument business, there a a few things you can check for yourself  before sending the laser off for repair.

Power is the first! If your construction laser is using standard alkaline batteries, try some new ones.  ( Sometimes even new batteries can be faulty, so check a couple sets).

If you are using rechargeable batteries, try some standard ones (if the laser has that feature) or plug into the main adapter/charger in the wall to see if the Laser will come on. If the laser comes on, maybe the battery needs to be charged or the nicad pack needs to be replaced.

If your laser gets wet, that normally is not good for the laser.  Moisture can get inside the Laser (depending on its IP rating) and damage the electronics in the laser.  Should this happen, remove the battery cover and place the laser in a warm area until it is completely dry.

Another good idea, if your laser fails, is to have a quick look in the instruction book. Many newer lasers include a troubleshooting guide to help solve many simple issues.