Screen lights up but no image - already replaced T-Con and Mainboard
A few weeks ago I completely tore down an LED TV that needed an LED strip replaced (TV would flicker then go out on powering up). Did that, put it all back together, screen lights up steady now but there is no picture.
those are diffuser sheets and have only to do with the way the light/picture looks. Unless of course you have by any chance reversed the polarizer it may be possible (highly unlikely) that you only have a white picture. Try to look at it with some polarized sunglasses and see if you can make out a picture. That would answer the sheet question. You should still see more than just the backlight. You need to let us know what exact model this is. Let us know if you have sound coming from your TV when you have a channel that you know is showing. Also, check the power board and see if the signals etc. make it to the main board. Post some images of all of your boarsd etc. with your question. That way we can see what you see, Use this guide Adding images to an existing question
currently working on this LC470DUE-SFR1-LG.pdf. Just out of curiosity, have you flipped the sheets. Mark them with a felt marker etc. before doing so."