After inserting USB lead, MacBook Pro won't turn on

I have a 13 inch MacBook Pro base 2012 model, which I bought in August 2012. Today, after inserting a USB cable, the laptop immediatley shut down, and won't turn on, it's dead. The charger as a strange orange flashing light, although only visable on close inspection, as it is very dim. The batery indicator lights on the left side of the MacBook Pro do not light up when the button is pressed. The USB lead in question was a 3rd party Lightning cable, however it had been working fine for a number of months prior to this. I have tried an SMC reset, and have also tried to reset the PRAM AND NVRAM. Nothing I have tried has resulted in success. While most of the MacBook is backed up, I would ideally like to avoid the hassle of getting a new MacBook, as i've got a number of very important files made in the last couple of days.