Power flex cable replaced, Phone not powering on.

[marbaby182]

Okkay, so I have taken phones apart before and never had any trouble.. but theres always something that can go wrong.

My dumbass went to the beach with my Note 2, and got sand in the audio jack port, and i cleaned it out as good as i could and well i still couldnt listen with headphones. So i decided finally to take the back off and get a better look. There was indeed sand still in the audio port and i gently got it out.

but of course i accidently tore the power flex cable /button ribbon on my way of taking the phone apart. so, i ordered a replacement flex cable. replaced it, and yay the phone does not still power on. this is the type of cable that doesnt need soldering, its just a plug in/push type.

so, the phone does NOT power on at all..
the screen DEF does NOT have damage to it, .. considering everything was perfect before my dumbass decided to take the back off the phone.....nothing else is damaged i went to extremes to take the board off even to make sure, everything is fine!

so, other than the power cable/button, what could be causing the phone not to power on at all now?