Sony Bravia screen looks cracked? Is this just a board problem or something more serious?

That can sometimes be caused by wall mounting screws that are too long or unevenly tightened. Sony seem to have stopped supplying parts already

https://sony.encompass.com/model/SONKD75X85J

I think based on this page, you could say there is an issue with 'XBR' sets and cracked screens! It says a replacement screen is about $1,000, so time for a new Samsung.
https://www.ifixit.com/Answers/View/467357/Replacement+screen+for+tv

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You either have a problem with your power supply board or main board. I would start with having the power supply fuse checked as well as the power supply board!

Do you mean the bm board? bm board is the designation Sony gives to the main video board on LCD TVs. Problems/distortions in an image or picture are usually related to either the BM board or the LCD panel itself or it's t-con board.
I'm not sure what you mean by "web like screen". Can you elaborate? The only thing I think of when you say web like screen is a cracked screen with spider-web cracking over it.

Hello
You haven't specified anything about the picture condition of your Sony KDL52W4100. Will you please give me some more details about it. Do the vertical stripe moves acroos and washes out picture? Do you get well defined picture on the resr of the screen? As you know, this is an Email solution, and I've to get your Email address to post my solution. Sometimes, I may have to upload the service manual [schematic diagram]for your TV to get you more information about the fault, and the method for rectification. So, give me as much as details as you can. either give me your email iddress or send an Email to me at [email protected]. If I may have to upload the schematic diagram and service manual, I can't do it by this window, as this window does not allow me to uplaoad PDF files by it. I haven't placed my solution to your problem till yet. Get me the details I asked for, and help me to detect the actual fault with your tv. OK

hi ;
there's a problem in screen driver of your LCD, if you lost your receipt,that's bad luck.
if you know how to disassemble the back case of the TV , you can try some RESETTING of connectors from LCD screen driver to display driver board

its only 50% chance to remove the line.
thanks.....

If you wish to get some details; visit the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.
Search the site by type in the "BRAND NAME" of your device; (Exclude the model number), in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

This tv problems are those long board call the LCD inverter boards,it is dead.TV should have 1 or 2 long boards that call the LCD inverter boards it it dead,these 1 or 2 long LCD inverter boards only job are to provide a backlight to the tv LCD screen panel to have screen light produce a picture.Tries websites like Shojimmy.com,Ebay.com to buy those refurbihes 1 or 2 long LCD inverter boards for the replacment.

LCD SCREEN HAS TO BE REPLACED YOU CANT FIX IT ONCE IT CRACK

Can you please post the picture or video of the fault?