Ow well in that case! I have a 2012 Macbook Pro non retina 15" that will not boot up at all. I have an awful feeling it is the logic board as it was in a bag that fell from the van seat when I had to break hard and suddenly. However it could easily be a connection that has come loose. I was going to take in somewhere......!

This is the non retina user upgradable version, the last of the ones where everything wasn't soldered in. I have tried the usual key combinations to force reset and boot to no avail. I have no issues opening it up but I would rather do it with a little idea of the potential issue. It was working fine right up until the "incident" so my suspicions tend towards the power connections.

I was quite surprised to see how much a replacement would cost even now!

Check this out.

https://www.ifixit.com/Device/MacBoo...ibody_Mid_2012

Other models are also covered.