My Box does not boot up

Hi.
Now that I've established that I have a supported device, I'll ask for help.
When I switch my box on it just hangs with the 'Zoomtak' banner on screen.
I followed the forum instructions to force a recovery by pushing the cocktail stick into the appropriate hole and bringing up an android screen with a number of options.
First I did the 'wipe cache' option and rebooted, with no effect.
Then I did the 'wipe data and restart' option (or similar). This brings up a droid and a message that seems to mean that it is working but it does not finish (left overnight).
I restart and the banner appears and then goes into the 'moving cross' pattern that I usually see when I boot up. However this just carries on but does not finish (even after an hour), when the 'cross' then stops moving.
I reboot and its back to the opening banner and nothing else.

Please advise re. my next steps.
Many thanks.

Thanks, everybody.
It has taken a time but I have been in private correspondence with our providers since my last post.
Nothing they suggested and I could do solved the problem and I have now received a replacement M6 box.
I think the customer service I have received has been first class.
Everybody has tried to solve my problem, and I just wish that I had been able to crack it without having to return the box!!
I guess there must have been a hardware fault?
The box now works well, I'm most pleased to report.
Many thanks again to all involved.