So, last night before I went to bed I tried one final time to flash the latest OpenVix to the box via the USB drive.
This time I removed the power cable, removed the Ethernet cable, popped the USB drive in one of the rear USB slots and re-inserted the power cable whilst holding in the up button. I kept the up button held for a minute or so but nothing happened other than the Mutant logo staying on the TV screen. I then repeated the process but this time started up pressing power button on front of the box for about a minute but yet again nothing happened other than the Mutant logo on the TV.
Annoyed yet again I turned off the TV and went to bed.
Today after getting home from work I turned on the TV and nearly fell over when I was presented with an OpenVix logo and what looked like a fresh install menu!! Not sure what happened I removed the USB, inserted the Ethernet cable and thus far I've managed to get internet working on the box per the screen image below.
It's nearly 4 years since I last set up this box so I've a lot of re-learning to do in terms of the 4 tuners, providers, EPG etc but for now I'm happy that the box at least appears to be live. Thanks guys for your help.