Followed this guide to replace usb pen but it boots once then wont reboot again

Hey so I followed this guide using a usb3 64gig pen on my edgerouter poe

https://lukas.im/2016/01/25/replace-broken-usb-stick-in-ubiquiti-edgemax-routers/index.html

And it works but the pen comes up with the wrong capacity.  So I popped it in my ubuntu desktop, umounted the partitions and extended partition 2 to the full 58GB.  However now when I reboot I only get this output:

Core clock: 500 MHz, DDR clock: 266 MHz (532 Mhz data rate)
DRAM:  512 MB
Clearing DRAM....... done
Flash:  8 MB
Net:   octeth0, octeth1, octeth2

USB:   (port 0) scanning bus for devices...
      USB device not responding, giving up (status=0)
1 USB Devices found
       scanning bus for storage devices...
No device found. Not initialized?                                             0
** Can't read from device 0 **

** Unable to use usb 0:1 for fatload **
argv[2]: coremask=0x3
argv[3]: root=/dev/sda2
argv[4]: rootdelay=15
argv[5]: rw
argv[6]: rootsqimg=squashfs.img
argv[7]: rootsqwdir=w
argv[8]: mtdparts=phys_mapped_flash:512k(boot0),512k(boot1),64k@1024k(eeprom)
## No elf image at address 0x09f00000

Can anyone help please?

Cheers

Andrew