Hi. I have a HP Pavilion dv4 with AMD ATI Mobility Radeon HD 4200 graphic controller. When I installed Win 10, I was able to use the HDMI port to watch movies in my TV. Some time ago, the HDMI output didn't work anymore. I guess some Win 10 update broke the driver or something similar. I updated Win 10, I updated the controller (it says I have last version) and I checked Windows and AMD web pages without finding any useful help. Any further idea?