OK so it was hissing, I see blue arcing on the tube on the cap,
is also covered in tobacco smoke/dirt. I tried some insulating tape
at first, which worked for a while but not the next day.
Anyway I cleaned up around the cap a bit untill I did not get much arcing
or any arching.
Anyway now when I switch on the picture is blurred, however it gets better
and after about 15 minutes it is back to normal or very near to.

So how do I make it work from cold, ie no blurred picture.
There was also some hissing this morning and some faint arching
but that seemed to clear up afer a few minutes.

I am thinking cleaning a larger area would help.

I am not sure why the picture eventually sorts it self out slowly
after switching on.

Is something heating up?