Latitude e7250

Hi all. My laptop was working fine and then it decides to crash, before it went like this the screen was glitching and then it would power off, and then turn itself back on. It would repeat this process. I have done an dialysis on it and all tests were fine. I have also rebooted it, turned it off and on 10 times, took battery out, drained excess residue, reset my laptop (keeping my files) and then reset my laptop and got rid of my files. 

It seems to be ok when I watch something on it. Like I watched a film on netflix last night and it was fine, its when I clicked out of netflix it would go again. I really need this laptop for college

 Does anyone know what else I can do? 

Thank you