Q: MacBook Pro won't boot at all

using my early 2011 15" MacBook Pro 2.3 ghz quad core with 8gb ram the other day, screen went black and had to do a hard shut down.  Ever since then when trying to boot up it won't progress past the apple logo with spinning wheel;  it either shuts down or goes to the blank grey screen indefinitely.

HEres what hat ive tried:

1.  booting in in safe mode doesn't work, once the bar finishes it goes to the apple logo and spinning wheel and crashes or stays on grey screen

2.  booting into the online recovery mode(cmnd r) I get the spinning globe it takes a few minutes for the bar to load then just does the same as above, crashes or stalls at grey screen.  Sometimes I won't get to the spinning globe and will get the logo the screen goes black with vertical stripes and crashes.

3.  Boot into single user mode, run Fsck -fy.  Multiple times.  Always says it's good; rebooting results in same as above.

4.  Reset smc and vram without any sucess

5.  Was able to make a bootable clone of the hdd using the lap top in target mode.  i can boot from this cloned usb hdd with an older MacBook Pro no problem.  However I can't using the 2011 MacBook Pro; won't even show up as an option to boot from when holding the option key at start up.  an older FireWire external drive bootable backup I made a few months ago show up.  But when trying to boot from it it does the same thing as abobe; crashes after logo or stays on grey screen

6.  I cloned the older MacBook Pro running Mavericks on to an older internal hdd and tried to boot off of it with same unsuccessful results as above.

i don't think it's the hdd as it will boot from the other laptop and I have access to my data.   I'm thinking it's the logic board?   Any other ideas or things I can try?  Apple says my laptop doesn't qualify for the logic board replacement program based on the SN.  LAPTOP IS ALMOST 4 years old and out of warranty and apple care.   The nearest Apple Store is 3.5 hrs away.

any suggestions or things I should try?  Thanks.