Last time I used my pc everything was okay I turned it off as usual, after 3 or 4 weeks I turned it on it didn't detect hdmi ( my monitor was not displaying anything) and also the keyboard and mouse wasn't being detected it restarted automatically after 3 4 seconds and turned on but still doesn't detect anything, my hdmi cable should be okay because I use it to connect my monitor to my laptop, what could be faulty here?