AMEIJ@vax.oxford.ac.UK (Jan Ameij) (02/08/90)
Question/poser for hardware hackers. Our office Mega 4 has died. At switch on it flashes the keyboard light, and if the volume is turned up throbs (bit softer than a click) loudly. Of course we know the safety implicationsof fiddling with these things, so we immediately opened it up and found the following... The throbbing is synchonised to the PS fan wobbling to and fro. If we flick start the fan the machine boots, but we get the "no keyboard" scream and no response to keyboard or mouse. If we unplug the PSU from the motherboard it starts fine (no need to flick the fan) and if we then plug it back into the motherboard the system boots and all is hunky dory. A bit of scope bashing reveals 'orrible spikes (about 25V worth) on the 12V line which runs the fan when it is quivering, and nice smooth volts everywhere else, anytime else. Any ideas, guys? My guess is that that big electrolytic beside the PSU has blown and is stuffing the 12V line, which in turn is stuffing the fan, but replies from experienced bods are very welcome. Jan Ameij Oxford University Department of Applied Metaphysics, ameij@uk.ac.oxford.vax -------------------------------------------------------------------------- Another message, primarily to Europeans... Since, alas, it looks as if Info-Atari16 is Doomed, should we be thinking about setting up a European Technical ST mailing list. It seems that most of the ST interest and expertise is over here and it would be nice to go on sharing it. Also, we might lose those whinging "Atari won't sell me a 100GFlop vector processor for $200 - do you know how much IBM that would buy" etc comments that waste all our time! Long live the European Third World (insult copyright RC, 1990!) Jan Ameij
pietrzak@picasso.CES.CWRU.Edu (John Pietrzak) (02/10/90)
In article <9002090802.AA05355@ucbvax.Berkeley.EDU> AMEIJ@vax.oxford.ac.UK (Jan Ameij) writes: > >Long live the European Third World (insult copyright RC, 1990!) > >Jan Ameij Now, don't go thinking everyone on this side of the pond is just like RC - not everyone can be quite as adept with the repartee. ;-) J P pietrzak@ces.cwru.edu