I noticed you still have the SD card in while trying to boot off of the old screen. Make sure there isn't any firmware files on the SD card. If you do have an update, rename it to 123.bin then when it's done just delete the file. You should be fine for the old screen. Thing you need to note though is you can't have any update firmware files on the SD card for the board when you're trying to use any of the screens.
Daniel i saw your 2 videos and you help me to identify the error this is what i did to fix it, i use a usb and the sd card at the same time, i downgrade the screen to the version 23 and in the sd i upload the firmware of the printer both from the web page you show in the video, start with bot devices plug downgrafe the version and continue qith the instalation menu, but fail remove the usb and start over the process with the sd no work,plug the oeiginal screen and yurn on and did a horrible big bip sound ao turn off ans plug the new screen and how work perfectly
To retrun to the stock firmware try to downlaod the firmware, change the name of the file an flash the printer; then use the tft file provided to flash also the screen. That should work.
I noticed you still have the SD card in while trying to boot off of the old screen. Make sure there isn't any firmware files on the SD card. If you do have an update, rename it to 123.bin then when it's done just delete the file. You should be fine for the old screen. Thing you need to note though is you can't have any update firmware files on the SD card for the board when you're trying to use any of the screens.
Daniel i saw your 2 videos and you help me to identify the error this is what i did to fix it, i use a usb and the sd card at the same time, i downgrade the screen to the version 23 and in the sd i upload the firmware of the printer both from the web page you show in the video, start with bot devices plug downgrafe the version and continue qith the instalation menu, but fail remove the usb and start over the process with the sd no work,plug the oeiginal screen and yurn on and did a horrible big bip sound ao turn off ans plug the new screen and how work perfectly
You need to conect the screen cable to the nebula pad
Ditto
To retrun to the stock firmware try to downlaod the firmware, change the name of the file an flash the printer; then use the tft file provided to flash also the screen. That should work.