[TenTec] Orion 1 VS Orion 2 Backlight brightness swapping A9 boards makes no difference?

[jon greenwood]

Have two Orion's one super bright backlight the other not so much. Both start up fine and look good once going but one is for sure not as bright.
So swapped the A9 boards thinking cap problem. makes no difference darker one backlight is still darker. Not bad but just not as bright. I opened front panels to check and both LCD's are identical and original. On the brighter one the PCB that the LCD attaches to is dated 2003 and is white. On the darker one it is 2004 and green. I see one component that is different. could be more. 
Question really is there anything wrong? I was repairing the A9 board for the Darker screen Orion and  now wonder if anything is wrong OR could it be the LCD needs to be replaced?Thoughts please73Jon N8MUS