4635 don't boot

[Marce11uy]

Hi guys,
I am trying to start for the first time a 4635 spare board in order to upload the last software release on my lab.
The issue is that this 4635H board (3BA73012ABAB VPM35) doesn't come with hard disk.
When I power up can't see any output connecting by serial to 4635 board (the cable was tested and work fine on CPU 7)

These are my questions:
1) Is it necessary the HD for starting the boot process ?
2) In case it is necessary, which are the compatible HD ?

Thanks in advance.
Regards,
M