joe@cbnews.ATT.COM (Joseph Judge) (04/09/90)
In article <807@runxtsa.runx.oz.au> ghhsmith@runxtsa.runx.oz.au (G.H.H Smith) writes: > >RE: SIMM upgrade to 2.5 meg causing problems <792@runxtsa.runx.oz.au> > . . . > > the system that you only have 1 Mb of memory. Other than that, > > the power supply would be the next likely candidate. Mac Plus > > power supplies are designed to put out _exactly_ the amount of > > power required by a 1-Mb Mac. The 256K simms draw less current > > than the 1-Mb simms that you've added. There is an adjustment > > that is supposed to be made to the power supply (a trimmer > > somewhere on it) that can tweak the supply voltages to compensate > > for the extra draw of the SIMMS. Outside of this, the only other . . . > >I have since removed the SIMMS and now have only 1meg again. The Mac >works fine. This would be in keeping with your theory about the >Mac power supply. Anyone know where the trimmer is ?? The Mac+ power board (the vertical one - in case you are not sure) should have a plastic cover between it and the case. On that, the various important places are printed. I think I remember it being about a third of the way up towards the front, labelled "- (hole here) +" something like that. My big question would be, where to stick the voltmeter to make sure that you are not over adjusting??? I sort of did my by "feel" - I do not recommend this!! Also, where is that place that sells a kit with better rated Mac+ parts (you know, the flyback transformer, some caps, etc...)?????? I called them once and they seemed pretty cool, the kit was about $50 ?? (my memory may not working here) It may be my mind (again) but my Mac seems hotter after new SIMMS. Maybe now I'll get that fan for the Mac - a necessary part, or so I've heard. Joseph.T.Judge@ATT.COM
dorner@pequod.cso.uiuc.edu (Steve Dorner) (04/12/90)
In article <15368@cbnews.ATT.COM> joe@cbnews.ATT.COM (Joseph Judge,45256,cb,1C393,6148607119) writes: > My big question would be, where to stick the voltmeter to make sure > that you are not over adjusting??? On the bottom of the ANALOG board, where the power connector is soldered in. Measure voltage between one of the pins and the chassis. I don't recall exactly which pin it was, and I don't have my documentation handy. Try them til you find the one that's closest to +5 volts, and adjust off that. -- Steve Dorner, U of Illinois Computing Services Office Internet: s-dorner@uiuc.edu UUCP: {convex,uunet}!uiucuxc!dorner