need help suddenly PC OFF

here video

part 1 youtu.be/I9gz1pd9ldI

part 2 youtu.be/QM1ASpaXQ6o

please watch full video

google chrome multi task then suddenly PC turn off totally shut down
need press turn ON PC then again open google chrome then also again  suddenly PC turn off totally shut down

i have tested software prime95 for processor test and RAM Test never had PC OFF too

what problem for Windows 10 for google Chrome

to many 20x times PC off 

Please help how to solve