Plugged in USB, MacBook turned off & won't turn back on.

Hi all,

I've got a Retina Macbook (A1502) that seems to be totally dead after plugging in a USB to charge my phone. As soon as I plugged the USB cable into the port, it abruptly shut off and now won't turn on at all. I've tried disconnecting/reconnecting the battery, letting it sit for a week to totally drain the battery, multiple chargers, SMC reset etc.

I took it to the Genius Bar and was told this was a known issue but that it would cost 500$ to replace the logic board as I'm out of warranty. I know this stuff can happen, but as a student with little money I can't afford to fix it right now and I'm a bit peeved that simply plugging in a USB would totally kill the machine (the usb cable wasn't even one of those really cheap ones!). I was hopeful that it was a minor issue after reading about multiple people with similar issues that were resolved after disconnecting/reconnecting the battery but I don't seem to be one of the lucky ones. I had a glimmer of hope after the orange light on the charger came on whereas initially there was no light, but still no boot up. Anyways I'd like to ask if there's anything else I could try or if my only option is a logic board replacement. Thanks for your help.