Debian installation on new hardware can be a hassle when it depends on non-free firmware support. A typical workaround is to use a Debian install image that includes non-free drivers, which is available here: Unofficial non-free images including firmware packages. Choose the right image for the kind of USB media you wish to create.

For this post, I chose (amd64 Jessie 8.4.0 netinst + non-free):

$ wget http://cdimage.debian.org/cdimage/unofficial/non-free/cd-including-firmware/8.4.0/amd64/iso-cd/firmware-8.4.0-amd64-netinst.iso

Find a USB stick (which you do not mind formatting entirely; all existing contents will be wiped out with this method), connect it to a working Linux box, and find the device pointer to the stick:

$ sudo fdisk -l
... (other devices) ...

Disk /dev/sde: 14.9 GiB, 16008609792 bytes, 31266816 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x156252ec

Device     Boot Start     End Sectors  Size Id Type
/dev/sde1  *        0 7800959 7800960  3.7G  0 Empty
/dev/sde2       20368   21199     832  416K ef EFI (FAT-12/16/32)

... (other devices) ...

We see that the USB stick is attached at /dev/sde in this case (IMPORTANT: this will certainly be different for you; do make sure the device is the USB stick you would not mind being wiped out).

Then create a bootable installation stick:

$ sudo dd if=firmware-8.4.0-amd64-netinst.iso of=/dev/sde bs=4M
$ sudo sync

TODO

There appears to be an issue writing to USB from isohybrid .iso image, from which I have not been able to create a proper bootable image. Check on this and update the post.

Reference

http://askubuntu.com/questions/372607/how-to-create-a-bootable-ubuntu-usb-flash-drive-from-terminal