how to stop my toshiba laptop satillite l455d-s5976 from shutting down on its own

[dmkratman]

My toshiba laptop turns o and then off in 30 seconds. what can i do

 

[J_E_D_70]

Is the battery showing charged?

Plugged in or unplugged to the wall? Does changing it change the behavior?

 

[1shado1]

When was the last time the fan was cleaned of all dust, and has the thermal paste on the CPU ever been replaced? It may be shutting down due to overheating.