For some reason since installing a new 1TB hdd and putting a 600 Gb partition on it, the optical drive can no longer be seen when running from an external usb enclosure using 16.04. Further, if the usb is disconnected and the system booted, the optical drive powers up bit will not activate the MATE live disk. BIOS system check of the optical drive shows a pass.
Can anyone help I’m no expert.
mike
Hello mate,
This post made me giggle a bit , i used to be a fast typer and a bit of a boozer when posting late at night 
after hours of computer frustration. So let me help you out.
I think you suffer from a lack of power.
Either too much power requested over USB, or your power-supply falls short. It could also be a problem with wiring or media. (when poorly written the drive needs to spin up and draws more power)
Anyway i think a better option would be to install from a (2gb+) USB-drive or SDcard ?
They draw less power 
Do you have one laying around ? Can you borrow one ?
- Make sure your download is good:
https://ubuntu-mate.org/how-to-verify-downloads/ - Then write it to USB:
https://ubuntu-mate.org/how-to-create-bootable-usb-drive
If you have any more questions let us know.
We will help you get through this
Hi and thanks. I’d come to a similar conclusion I have decided to use the original ubuntu disk in a usb casement, put the Tb disk in the internal tray and use a usb live flash drive to inistal. I can then transfir my orig