Galaxy A51 black screen

[wnibraj]

Hi, i unclocked the bootloader and flashed updated to Android 11 on my A51 few weeks ago and everything was going fine until yesterday i plugged it into charger and after a few minutes when i tried to unlock the phone, the screen doesn't show up. eveything's black. i tried forced restart method and other possible methods but none worked. the display only shows samsung logo while restarting and while in recovery and download mode but once it restrats completely, turns black again. i thought relocking the bootloader will do the job so i go to download mode and select LOCK BOOTLOADER( i didn't know if it was correct as i have 0 knowledge regarding these). and then it's stuck in download mode and no methods worked to get outta it.after a few hours, several while vertical lines and then blue dots(in the corner and surrounding the fingerprint sensor) start appearing on the screen and increases gradually with a break. however, i was able to install the custom firmwire (android 10) {although samsung officially released android 11 on A51s} using odin and then wipe the phone completely but now it restarts and then back again on the black screen. what can i do now? thank you

 

[mustang7757]

Hi, welcome to AC!

Where did you get the firmware and Odin from ?
Did you use all 4 slots in odin ?