LCD touchscreen not working

I recently replaced my Amazon M2V3R5 Kindle Fire HD 10 2019 9th Generation LCD touchscreen that was shattered. I was careful removing and installing the new touchscreen. I’ve replaced the black Antenna coax wire due to I accidentally broke off the end connector and replaced the battery due to it was sitting uncharged for a while. I double checked all my connections and before I reinstalled the back cover, wanted to make sure it turns on and works. But all that happens is the screen lights up and it makes the turn on sound but no actual display on the screen. I’ve even did the 40 second hold down hard reset and nothing- still the same situation. If anyone has any experience with working on these devices. I’m asking for help and suggestions on what I can check. My next step was going to try replacing the MB/LCM flex cable which no one seems to have in stock right now. I’m hoping to get an answer from someone who’s pretty handy and knowledgeable about these devices on what I can check. I know these devices don’t cost much but before it broke I have important documents and photos I’m trying to retrieve off the device. Any help would be appreciated.