I have a mid-90s-vintage GraLab Model 545 timer that I use for my cold light enlarger. I've been very happy with it, except that, over time, some of the buttons have begun to act like there's dust or something that is preventing a good contact from being made. I frequently have to press some of the buttons numerous times to get them to act. Of course, the problem is worst with the buttons I use most, such as the "Start" button. I opened the unit up (despite the warnings not to), and noted that the buttons appear to be self-contained units souldered onto the PC board, and there does not appear to be any way for dirt to get into them, or to remove it once it is there. I have 2 questions: 1. Has anyone out there had similar problems with the 545? 2. If so, how did you fix it, or did you? Actually, here's a 3rd question: Does anyone know whether more recent models of the 545 have been engineered to eliminate this problem? Thanks muchly, and enjoy these cold winter months in the darkroom! -- Paul.