The eraser I always saw recommended was a "pink pearl" which was in commonly available supply at any office supply store. I never bought into the notion that the substance I was removing was "corrosion" for the simple reason that the backplane connectors and the PCB's were gold-plated. Since the eraser always left a clean gold plated edge connector, I quickly concluded it was dirt and not corrosion that was accumulating at the interface between PCB and backplane. I found much less of this occurring in clean environments where dust didn't accumulate in the equipment cabinets, so I did what I thought necessary to exclude dust from all the cabinetry, and, guess what! ... There was much less "corrosion" in the cleaner boxes than in the dirty ones. Dust doesn't cause corrosion, does it? It could cause abrasion, but I doubt that's at the root of these problems. My question would have to be, "How do you clean the backplane connectors? Dick -----Original Message----- From: John Wilson <wilson(a)dbit.dbit.comTo: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.orgDate: Monday, March 13, 2000 2:13 AM Subject: Re: Red Erasors to >> clean gold fingers, I would fully expect any abrasive material to remove >> some of the gold. How much? Darned if I know. >Somewhere in the old DEC maintenance fiche there's a discussion about this. >They claimed the amount taken off by an eraser was pretty significant >(something like 1/10 of the plating each time you rub it down with the >eraser, but maybe they were a tad enthusiastic in their tests) and so it >was a really bad idea, they had some vile chemical that they wanted the FS >folks to use instead. >John Wilson >D Bit