I just replaced the hinges on an SL500 2746-EKU. While disassembly and assembly went well, the laptop doesn't power up. Instead, when the power button is pressed, the green light around it flashes once and that's it. If I plug it in, that same light flashes continuously, with or without the battery inserted. I have double and triple check all cables are connected. Is there something wrong with the board or??? Any help would greatly be appreciated.