I can't flash Copter 3.5.7 but no problem with other firmware

ArduCopter Copter 3.5
1

Hi, I have a pixhawk and I’m trying to flash copter 3.5.7. At the end of flash process I heard 3 tones like this:

but nothing else and I can’t connect to the board to make configurations. Mission Planner say that I have to wait for musical tone, but they never happend, just 3 tones.
If I flash rover o plane or even arducopter beta, it works ok.

2

never mind, Qground control alert me to check SD card. I haven’t one installed.
Mission Planner should make that alert too…