Speaking of issues, this is when you know something could be wrong with your unit. Firstly, when you are installing new batteries, ensure that they are actually new. Batteries will self-discharge over time and it is possible that they are simply out of juice. Also, ensure that you actually install them correctly into the unit. If you know for a fact that the batteries are new and that you have installed them correctly and the unit still will not turn on when you walk across it (assuming you are doing so in a dark room), then you may need to get ahold of the seller or manufacturer.