Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: $Revision: 1.6.2.16 $; site ada-uts.UUCP Path: utzoo!linus!philabs!cmcl2!harvard!think!ada-uts!callen From: callen@ada-uts.UUCP Newsgroups: net.micro.mac Subject: Re: Mac hardware problem Message-ID: <27800001@ada-uts.UUCP> Date: Mon, 28-Oct-85 09:25:00 EST Article-I.D.: ada-uts.27800001 Posted: Mon Oct 28 09:25:00 1985 Date-Received: Fri, 1-Nov-85 02:08:58 EST References: <3198@mhuxd.UUCP> Lines: 25 Nf-ID: #R:mhuxd:-319800:ada-uts:27800001:000:1297 Nf-From: ada-uts!callen Oct 28 09:25:00 1985 > About a month ago I completed the DDJ upgrade. Everything went well. > A few days ago my mac quit. On power up the machine buzzes and > displays 4 sad macs. The macs are located in the centre middle > centre bottom. The two other macs are split at the edges of the > screen and wrap around. The numbers under the sad mac vary but > are either 04FFF8 or 020000 (or some variation). > Anybody have any ideas? I've done a half dozen DDJ upgrades and never seen THAT specific problem, but I've had to shoot OTHER problems. They have (so far) ALL been caused shorts between pins in the memory array (no comments about sloppy soldering, please). Run the continuity tests listed in the DDJ article, and check for shorts. Unfortunately, if you find a short and it involves only the "common" lines in the array (which is nearly all of them), you may have to pull ALL of those nice new sockets to find it (someone PLEASE tell me that there is a better way...). Pull the sockets one at time and re-test. So far I've been lucky - one short involved pin 14 (which nailed it to a single chip), and the other was the second socket I pulled off the board. The DDJ upgrade is nice and cheap, but it's not for the fearful or the novice soldering hacker... Jerry Callen ...ihnp4!inmet!ada-uts!callen