OK so I just now copied them, and it's still not working. maybe reboot the tablet, I don't know. where do you store your roms? that might make a difference although I have it pointing to the right directory.
I just remembered something else that might be causing the problem (I ran into this issue). Maybe you are running into the same issue.
In a nutshell, there are 4 files that the emulator can use in addition to the game file. The files are exec.bin, grom.bin, ecs.bin, and ivoice.bin. When the emulator loads the game, it also looks for these files in the same directory and loads them as well (if it finds them there). The problem is that there are a handful of games that are incompatible with ecs.bin and ivoice.bin being loaded and can cause the black screen you are seeing.
The majority of games were only designed to work with the main console. Stick them in a directory with only exec.bin and grom.bin.
A handful of games were designed to work with the ECS and/or Intellivioce. Stick these games in a different directory with exec.bin, grom.bin, ecs.bin, and ivoice.bin.
So why do we see this incompatibility between some games and ecs.bin and ivoice.bin but not see this same issue with same real games and the ECS and Intellivoice? Well, at least for the Intellivioce, the Intellivioce looked at a couple pins on the game cartridge hardware and if they were not grounded, then the Intellivioce hardware knew it was connected to a compatible game and would then activate the rest of the Intellivoice hardware (otherwise, the Intellivoice left itself deactivated and out of the way of non-Intellivoice games).