Are bias and brightness exactly the same? I know they both affect the darker levels,but It looks like brightness affects more the dark levels and bias affects more middle levels.Or am I wrong? I'm trying too balance the gamma.The tv does NOT have 10 point controls.
You should always re-check Brightness after adjusting any of the bias/offset controls and vice versa.
Gain controls affect the brighter range of each color (R G B)... so if you adjust any of those, you should re-measure your 100% white level to make sure it is still where you want it to be and adjust Contrast up or down if your 100% white got too bright or too dim (but you need a meter for this, you would never see it by eye).