QUOTE (DAZZZLA @ Jun 12 2006, 04:31 PM)

Yellowing is usually an indicator that the light is being clipped by the triplet especially when only one edge is being affected. Your lamp or triplet may not be aligned correctly. Measure your distances to the centre of the triplet and to the centre of the arc and make sure they are both aligned correctly with the centre of the LCD/fresnels.
DJ