I have the same problem as Why does my external hard drive not boot
I tried all suggested solutions on the web even I removed the internal hard drive and I let the installation use all the external hard drive size to install it but it still not able to boot.
laptop: emachine e730* core i3 external hard drive: Apacer 1TB AC233 USB3.0 Portable External
usb 2-1.2 device descriptor read/64, error -110 new high speed usb devise number 4 using ehci_hcd usb 2-1.2 device not accepting address 5, error -110 unable to enumerate USB device on port 2
– Wael Mahameed Apr 16 '13 at 22:10