I believe the problem is now resolved as I received a replacement yesterday and I've done all the updates and it's working fine.
There was an announcement on Amazon earlier this week:
A firmware download was released to Windows Update to resolve a potential issue where some Linx 1020 might struggle to upgrade from Windows 10 Anniversary edition (RS1) to Windows 10 Creators Update (RS2). During the release we received feedback that some devices installing the update would no longer power on.
The firmware has since been removed from Windows Update so no other customers will be affected.
We are working hard to ensure that all customers affected by the problem are having their devices replaced as soon as possible. If you are affected and have not yet contacted us, please do so via the Linx Support email – ******@exertis.co.uk.
Regards,
Linx Team
Finally a solution - but this has cost someone a fortune..