I have a router cisco 2800, but always is in rommon, the message show is:
device does not contain a valid file system
dir: cannot open device "bootflash:"
rommon 8 > dir usbflash0:
Checksum failed on c1840-usbfslib-m
Expected checksum: 91d6, calculated checksum: 4527
open: file "c1840-usbfslib-m" not found
open(): Open Error = -1
loadprog: error - on file open
cannot load the monitor library "bootflash:%c1840-usbfslib-m"
from device: usbflash0dir: cannot open device "usbflash0:"
what suggest me, for fix this equipment....
It appears the usb device has a corrupted image. You should be able to download and copy the your necessary router image to the usb device and reboot the router.