2012 MacBook Pro Won't Turn On

Hi all,

I have a 2012 macbook pro that won't turn on. When you press the power button, the light on the front blinks once, pauses for a couple of seconds and then blinks again, It will not boot up, and the screen stays black.

I've tested the hard drive and RAM in another computer and am sure they are working fine so I'm inclined to think it's either a logic board or power supply failure (not sure if the power supply is separate from this logic board?). I haven't replaced the battery, but even when the laptop is plugged in, it will not turn on.

Does anyone have a similar experience or idea what could be wrong?

Thanks!