Tablet touch is working but no display after installing new screen

Hello

The screen of my tablet was broken, but display was there, but no touch. I removed it and placed a new in its place.

Before removing it, LCD was giving display, but on putting new one, there was no display on new screen. Then i checked again with the old one, surprisingly, there is no display on old too.

Now with the new one, i can hear vibrations, and even while touching the screen, i can hear touching sounds, as i am dialing a number, but screen is totaly black.

Note: i changed the flex cables, with the screen and on motherboard without unplugging the battery.

Kindly advise some solution for it. I have attached pictures of the tablet with flex cable.

I never received any reply from ifixit before, please dont disappoint this time.