Internet problems

Problem svolved, cables had slipped out partially. put it back in place and havent had any issues since!

This might be in the wrong sub but i couldnt find a pc help sub. So if it is feel free to tell me eventually move it or something.

I have been experiencing high ping at random intervalls to complete internet loss for the past 2-3 months.
Yesterday i contacted the service provider and they said nothing was wrong with their lines.

So i was just wondering if someone has any tips on how i could see if my pc is the problem so i can rule that one out.
Might be the router but i just want to be sure its not my pc before i try a new router.
Competetive games as league is totally unplayable and at times i cant even complete a heartstone match. :L

Thanks for any help or advice