Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!ucselx!bionet!agate!ucbvax!tut.cis.ohio-state.edu!sei.cmu.edu!fs7.ece.cmu.edu!fs7.ece.cmu.edu!barvian From: barvian@ece.cmu.edu (Scott Barvian) Newsgroups: comp.sys.mac.hardware Subject: Re: Tragic SIMMS installation Message-ID: Date: 20 Apr 91 01:53:10 GMT References: <41443@cup.portal.com> Sender: news@fs7.ece.cmu.edu (USENET News System) Distribution: usa Organization: ECE Dept., Carnegie-Mellon University Lines: 32 In-Reply-To: Drako@cup.portal.com's message of 19 Apr 91 19:50:48 GMT In article <41443@cup.portal.com> Drako@cup.portal.com (Chris Del Grande) writes: A friend of mine installed two 1 meg SIMMS chips into a Mac SE a few days ago to achieve a 2.5 megabyte configuration, and apparently everything went fine exceptuUpon startup, the monitor was filled with vertical black stripes and the machine never made it past the 'Happy Mac' startup icon. He first suspected that he had accidentally clipped the wrong resistors (R35 & R36) but upon further examination everything was in order. The 1meg chips were also in the proper rows/banks, etc. All wires and cables were intact also. The mac still would not startup properly. He took the machine to a local Mac dealer who said it was a fried CPU (I believe) and charged him > $400 for a replacement. Does this seem in order? My friend says that he didn't touch any of the other components and such,so just how sensitive are these inner components to the human presence. I've come across black stripes and/or checkerboard patterns when I've installed memory in the wrong slots and/or snipped out the wrong resistors. Are you really sure you did it right? I think there are at least 3 combinations of bank/resistor combinations, one for a Plus and for two different flavors of SE. And certainly ESD (static-induced damage) is easy enough to cause. A dry room and/or a dry day and you're just asking for trouble. But a wrist strap (grounded to a suitably safe place) just about eliminates that possibility. You don't necessarily have to touch a given chip to "zap" it- if you touched a board trace or connector and created a discharge, the "least protected" circuit is most likely to be harmed. "A fried CPU", given the symptoms you describe, doesn't sound likely. But anything is possible. I'm not a doctor. Nor do I play one on TV.