I have a Dell XPS 15 9560 that will not POST. When trying to power on the LED power light will come on and stay light solid for one minute and then turn off. There are no beeps, no LED flashes and no caps lock LED comes on. I have tried removing the internal battery but get the same results. I have tried pressing F3, F8, F12, etc with no luck to get it to BIOS. The screen is always black. The fans spin up momentarily at the end and then the system powers down.