black screen, power button = flash light, unrecognized by computer,

Hello!!! I've got some problems with my phone. In fact, there's a black screen and sometime the logo fastboot but it's bloqued and impossible to enter in recovery mode. When I try, at each time I press the power button the flash light is on!!! My phone is not recognised by my pc. So what can I do? Buy another one?
Thank you in advance