my lenovo Z51-70 laptop shutdown automatically after turning on power

[abdo2262010]

my laptop lenovo z5170 suddenly shut down and i tried to turn it on again but it automatically shutdown after few seconds.
i tried to open the lap body to find any reset key or to disconnect the battery but i couldn't find or do those 2 things.
please help me 🙁

 

[mohamed_hassan_2017]

I got about the same problem everything seem to be fine untile playing on the external gpu
MY battery alarm tells me to the battery is weak and need to be replaced
I think this is the problem but is it a must this is what i don't know