OK - Its working again - Next Problem
So, this morning, as a bit of a hope, I try the thing again.
AND IT WORKS
Must have got knocked in my bag and got "unstuck", which is great.
Next problem - I will be back in Australian for 2 weeks in about a week. Does anyone know the fan type and/or make so I can take it to a shop and get it fixed.
PS - Sent an email to HTC. The issue has been sent to a senior tech. I have told them it works and have requested the fan type/make and instructions for replacement (and explained my location situation). Lets see how that goes.
The thing is still technically in warranty, but I am not going to have enough time to send it to HTC, wait for them to look at it and then get it back. I am only going to be in Aust for 2 weeks, not 2 months (OK, that was a bit harsh - sorry HTC