Subject: Re: System error 0911 on IIgs From: Rubywand Date: Mon, Nov 30, 1998 15Ç29` Message-id: <36631C3F.96CC17FA@swbell.net> Glenn Fisher writes ... > > Sometime when I power on my IIgs, I get a > "System Startup error 0911" > Can anyone tell me what this means or point me to a URL where I > might find out what it means. I do not have a IIgs manual. .... The Apple IIgs Hardware Reference and The Apple IIgs Firmware Reference are good to have; but, they do not cover this problem. Nor is it mentioned in the tech notes. The source of the 0911 error (0400 error on the ROM-00 GS) was nailed in a 1988 issue of Computist. Basically, one of the two major ADB IC's malfunctions and this malfunction is temperature dependent. As Paul observes, reports vary a bit regarding specifics. My experience has been that the IC bombs over a range of relatively low room temperatures. On our original motherboard, the bombs first became a bother during summer when everyone in Houston runs their air conditioners and rooms are often cooler than normal. We added a System Saver GS. Its fan cooled the GS interior and the frequency of crashes _increased_. We essentially eliminated 0911 crashes by placing a 12V panel bulb (bullet-shaped, about 50ma or so) on top of the temp sensitive IC and enclosing it with duct tape to form a mini-oven. The bulb was powered from the +12V pins near the back left side of the motherboard. Anyway, tests showed that crashes went from 3-4 per day to just 4 over a two-week period-- all of these crashes were at or soon after power-up before the bulb had a chance to warm things up. The mini-oven fix is not difficult to try out. It's been a long time (we finally swapped-in another motherboard), but I'm pretty sure the actual culprit is the ADB Glu IC (a square IC near the right front at the I-12 position on the motherboard). The other posibility is the smaller ADB Controller at the I-14 position. Rubywand