That's cos it's digital. Any signal interference does not appear as fuzziness or furriness or speckly noise, those are artifacts of analogue systems and their gentle degradation from perfect to fucked.
If your cable, or any other part of your rig is failing, you will get "ticks", "jumps", "squeaks" and coloured, often green, flashes......in fact the exact same shit you get with satellite telly on a day with apalling atmospherics or extremely high winds, or with incomplete avi/mpeg files.
You are spot on about contrast etc. I'm not sure settings from the net will really work, unless the devices are all identically calibrated internally.
My Hanns-G 28" monitor (which is my TV, had to do it that way, TV's make wanky monitors, but monitors make great TV's although you lose the shininess of TV, replace by a more gritty realism of colour.) uses an auto contrast feature, which while it's normally the sort of thing I'd touch with a barge pole, does work rather well. When bright things come on it ups the overall brightness and contrast, and when it's showing dark scenes they both reduce. Very effective, except sometimes in driving games where there is a lot of dark cockpit interior in-frame, which darkens the whole lot, including the outside world.