comanche12

Using a bios editor, you could probably set a higher voltage than the default. Do take caution when doing this, because an increase of 0.1v increased my temps 10c under load... (ATI 5870m, your 680m is probably more efficient, but still do take caution)

I am not to familiar with this technique, however I have heard of some people successfully repairing damaged vbios flashes with a technique known as "blind flashing" where you boot into a DOS usb device with a KNOWN WORKING vbios, and flash that way.

I would suggest looking up M17x motherboard beep codes for starters. my guess would be that the vbios of your new card are conflicting with the original m17x bios.

These new Haswell-line cpu's are quite finicky with memory. I have seen people run standard DDR3 in some haswell notebooks just fine: (it was a newer asus gaming notebook, not sure of the model) however this does not seem to be the case with you.

Nice work! I have taken my cousin's apart to replace an lcd cable, and it was without a doubt, not the most fun i've had.