I have two PCs using exactly the same hardware. They come with windows preinstalled by the supplier.
I've removed windows and installed Ubuntu on one of the devices, and am experiencing two problems:
When connected to some TVs the image overscans, i.e. parts of the image are missing from around the edge of the screen, as if the image is 'zoomed in' slightly.
The colours on the image are very dark.
With the windows version, using the same TV, neither of the above problems exist.
Additionally, when we use a (more expensive!) Samsung TV, these issues don't occur even with the Ubuntu device - I think it's a bit smarter and is detecting the best settings based on the output.
Does anyone have any idea what could be causing this? Could it be a driver issue? What information (other than the image itself) is passed to the TV via HDMI?
I've resolved the overscan issue using the TV's settings - switching the TV into 'PC' mode does the trick for that.
The image can't really be corrected via the TV's brightness/contrast settings - if I put the brightness up, blacks become light grey. Furthermore, I need this pc to work reliably on different TVs, without customising their colour settings each time. The fact that the colours are fine on windows suggests this is likely either a driver or a config issue to me.
The devices uses built in Intel graphics from an Intel Celeron N3350 processor.