I have been tracking a number of failures of LED's mounted in the lower position of dual LED assemblies. The failure mode typically has been an open junction. Because I have been able to restore LED illumination by heating the lenses on a number of the rejected LED's, I suspected that the failure mechanism was likewise based on the application of heat to the lens. As the lens heated up, the plastic distorted, resulting in open junctions. Since it was the lower LED which would always fail and the devices were edge-mounted, it was natural to suspect an improper height adjustment of the solder wave. This condition was verified by observing that the lower LED's indeed did become immersed in the solder. Based on this observation, the wave height was reduced, and the failure rate dropped dramatically. Six weeks passed and the failure rate increased again. I have been assured that the solder wave height has not been readjusted. Anyone have similar experiences or thoughts on the failure mechanism? Myron Papiz