I have a Vaio VPCS131FM, which has an Intel i5-460m cpu. It uses Ironlake graphics. If I plug it into hdmi while on ac power, after about 5 minutes the monitor starts getting little lines and dots on it. After a couple more minutes, the screen will lose connection every 30 seconds for about 5 seconds each time. These issues do not occur on battery, or on Windows 7/10 on the same laptop.
This happens on several different monitors and with different cables. I've tried changing the resolution and frequency. This happens on Ubuntu 14.04 LTS and 16.04 LTS, with various desktop environments (Unity, XFCE, Mate, Gnome).
I have done all the usual updates, and I don't know where to go from here. Any ideas on how to get a stable hdmi connection?
