Could be either. Have you no paperwork to say what work they have done?
How old is the laptop? When did you buy it and from where?
Also what was the fault that caused you to send it to the Tech Guys?
and of course, what make and model is it?
Best Black Friday Deals 2017
How modern book design was influenced by illustrated manuscripts
Best Black Friday Apple Deals 2017
Les meilleurs logiciels de montage vidéo gratuits (en 2017)