In the last few days i made some tests with the same expected results..
1° test: only one module in the clusterboard to test the module and the sd card.
Boot perfectly, i tested all modules on all slots and they works fine.
2° test: all modules on the board.
Module on slot #2 and #4 doesn't boot up. During the fist seconds on the screen i can see some caracters but it seems that the board stop trasmitting data.
The "rx" led on UART module stop blinking and i never car reach the login line.
On all the others slot after the same characters i can reach the login line.
The leds on usb side on slot from 1 to 4 are stationary on, the others are off
On all the other slots the boot work fine
So, what tests can i do now?