A definitive answer requires you to provide the exact model number -- XPS 9333, 9560, etc.  That error can relate to a bad reserve (CMOS) battery, but by itself, that won't prevent powerup so there has to be another issue with the system.Unplug the system, disconnect the main battery from the system and hold the power button for 30 sec.  Reseat (remove and replace) the memory module(s) if they're replaceable. Then try powering up again.  
My laptop won't power up. The front light is flashing one white and 3 amber. I know that the battery is full. How can I get it to start up please.
1 White and 3 amber flashes