When the MEGA65 boots up with the OpenROM, this means the SDcard is not properly inserted (you've already checked this).
or the SDcard is corrupted.
In this case i would suggest, to do a backup of the SDcard to your PC, then utilize the SDcard with the MEGA65 (press ALT while powering on and use the SD utility).
after that copy the SDs PC backup back to the SD, put it back to the MEGA65 and try again.
All components on the MEGA65 R3 board are high quality. so from mechanical point of view, there shouldn't be any issues with the SDcard.
EDIT: PS: it's always usefull to do a backup of the SDcard ![]()