lumia 720 screen freeze

The screen does not light up and the phone appears dead.  However when I Call the number I get a ringing tone but there is no sound from the nokia 720.  What could be the matter and how can I wake up the phone ..

yes. this solved my problem. Hold the  volume down button and the power button till the phone vibrates.

cant even reset

so  i have had  this  phone  for less  than  10  hours , set it   all set  up  as per  YOUR instuctions~ within  4 hours   it's  F******D !!!  screen  frozen , waited  & waited   went  to  the  www  for  tips  & came  to  this  page   tried  all  the  tips on this  page   held  the  power  button down for  5  mins  on many occasions to  no avail ,plugged into  the  laptop ,  guess  what  F**k all ! in the  old  days  tip one #  was  remove  the  battery , no can  do !~ only apps  loaded  are  face  book , RAC &  drive, 4   F*****G hours  i have  been  trying   now, can  not  recieve  calls  , i tried  from my land  line, ~can  not  make  calls  as  my phone  is  for  all intent  DEAD !   i should  apologise  for  the  language  but  i won't  unless  someone  can  sort  this out, as it  would  apear  it  is  not  a  faulty  phone  but  a  problem your  end  that  i would  rather  like  sorting swiftly as  it  would  apear  from this  thread  so  would  many others !!(oh sorry can't  get a windows  fix  via  phone  as  it's  DEAD !!)~ this  phone costs £249.00 via  02 & SUPPOSED    to  be  cutting  edge ? !!! any sensible  tips on how  to  fix  other  than slinging  the  thing  in the  bin ?

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binnyjeshan wrote:

Hi my new Lumia 720 sometimes freeze up and only way out is a reset..... Any tips please? Is this a known issue? Is there any fix update planned to be released?

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I just want to say that I have the same problem with the phone. After some heavy usage, e.g. taking tens of phots, or using GPS continiously for 10 mintues, sometimes (not always), and after I close the screen manually, the phone now respones to nothing! It behaves like zero power! I cannot restart, cannot do anything. 

And when I plugin the power, the phone becomes live again. I can see that there is enough power left. So definately a software issue! Nokia, please fix this!