Very bright screen after replacing screen

Hi I've just replaced the screen on my iPod touch 4th gen. I turn it on and it's very white but I can still see the apple logo. When using it again the screen is very white but can just about make out the icons. When I go into folders some parts of the screen overlay and it gets all confused, but it does all work software wise.

I'm not sure if this is the same as the white screen of death because I can see it (just about).

I've tried the following based on other pages on this site:

Resetting using the home and sleep button

Resetting using home/volume up/sleep button

Factory reset on iPod

Resetting whilst plugged into laptop/iTunes

Disconnecting then reconnecting the screen

Putting the sponge bit from old screen connector onto new connector

Checking light sensor for exposure (all intact)

Checked for pin damage on video connector and power connector (no damage seen)

I'm currently letting it drain to see if a dead battery might give it a more heavy reset. Only thing I haven't checked is if it's the screen itself but would have to send it back so wanted to hear other opinions first.

Any other solutions welcome as I've tried every trick and video I can find to solve this. Thanks.