c60a-4ag@web9a.berkeley.edu (Robert Menke) (05/08/88)
Something very odd happened about four hours ago. I was using my II to download some files so I used my roomate's SE to copy some disks for a friend. Suddenly, the SE died. Screen went blank, sat there like the power went off. We checked the plug and found it had come out part of the way. So we plugged it back in and... nothing. Not even a sad mac icon. Something is happening, because when the switch is turned on, a couple of quiet clicks come from the computer, but that's it. I know it's not much to go on, but I wondered if anyone had had this happen to them before and if so, what was the cause. My guess is that a fuse blew in the power supply. My friend argues that if it was a fuse, then we shouldn't hear any noise, i.e. the clicks, from the SE. We cannot find out what went wrong until next Thursday when we can take the machine in for repairs. E-mail me any ideas. I'm sure the problem is something obvious. p.s.: It didn't overheat. We let it sit and cool for three hours but nothing happened when we turned it on. How Wabewalker became one with the net: | >LOGIN | Robert Menke >TYPE "RN COMP.SYS.MAC" | c60a-4ag@widow.berkeley.EDU >READ ARTICLES | (Still an EE wannabe...)
andrews@uicsrd.csrd.uiuc.edu (05/13/88)
Clicking noises are exactly what you hear when you overload or short a switching power supply ( the kind inside the SE). The supply tries to come up, sees a load that is too large, and protects itself by shutting down. Since you did not mention any hardware mods (or did you?), it sounds like something in the supply blew. A blown fuse on the 115 AC side cannot be the problem, since the machine would be silent in this case. However I don't know if the DC outputs of the supply are fused (I doubt it). If so, this could cause the symptoms, although I really don't know that much about switching supplies. Good luck. John Andrews