Video won't show up in tablet's screen but it does on my tv with dock

Hi! Im new here and Im looking for help since my switch wont show anything on its tablet screen, but works perfectly with the dock.

a couple of months ago i bough an used switch(tablet only) off ebay so i could have spare parts for my original switch since i changed the shell case off it but ended up the charging port of my left joycon. When i replace it i went into changing the frame shell to a new one. I followed the tutorial to replace the frame correctly and trying to be careful into not breaking the cables. After finishing, I put everything back together but now my screen tablet won’t show up but the video shows perfectly in my tv with my dock.

pls help :[

It is most likely an issue with the LCD connector. I woukd take the back off and take a close look at it to see if the cable is correctly seated. These connectors are very easy to damage, due to his the cable is carved round to get into position.
If you are not sure, take some pictures of them so we can take a look also.
You will need to upload the pics elsewhere and post links with some extra spaces.

I hope these pictures are ok, do you think I might have to replace something here?

ht tps ://www.reddit.com/r/tronicfixphotoshare/comments/rtemrw/this_is_for_tronics_fix/

Have requested access to the subreddit, at the moment I cant see the pics.

Try now! sorry for the inconvenience

Ok, so I can see some corrosion here, that you should wash with IPA before it gets any worse.
I think the actual cause of the issue is the lcd ribbon however, I can see a gap on on of the traces. Someone pretty skilled at soldering could maybe repair it, but otherwise it would need a new lcd. But that connector will need some good cleaning first.

Thank you so much for the help!