rashid@magnus.ircc.ohio-state.edu (Robert G Rashid) (02/18/91)
I hope I have chosen the correct group for this problem. I have a Mac Plus which has been showing some erratic behavior. On startup, periodically I will get the SadMac icon with a variety of numbers. The most frequent (repeated the last three bombs) has been 03FF00. I am unable to identify what this indicates. I thought the 03 meant a memory problem, but my listing of codes does not indicate what the FF00 would point to. Of importance, I have a Supermac 2Meg upgrade that was installed in 1987, and I am on my third power supply board (replaced 1 year ago). I am also having a real problem with the machine when trying to insert a disk. If the machine has just been turned on, disk insertion (it normally starts from an external HD) will cause a system bomb (ID=02, or sometimes 03?). Frequently, insertion will also cause a reset, periodically followed by the infamous SadMac. Restarting, and then inserting a disk usually results in normal performance. (but not always :-(...). My first suspicions of the cause(s) is the memory board. Since I have been considering an upgrade, I want to insure that doing that will cure the problem, and not be money down the drain (sure, I can use the memory in another mac, but my other mac is a portable...). Any and all help would be appreciated. It can be posted here, or to me by email. -- | Bob Rashid | Rashid.1@osu.edu | | College of Dentistry | 305 W. 12th Ave. | | The Ohio State University | Columbus, OH 43210 |
omh@cs.brown.edu (Owen M. Hartnett) (02/20/91)
In article <1991Feb18.142402.17575@magnus.ircc.ohio-state.edu> rashid@magnus.ircc.ohio-state.edu (Robert G Rashid) writes: >I hope I have chosen the correct group for this problem. This is the place! >I have a Mac Plus which has been showing some erratic behavior. >On startup, periodically I will get the SadMac icon with a variety >of numbers. The most frequent (repeated the last three bombs) has >been 03FF00. I am unable to identify what this indicates. I thought >the 03 meant a memory problem, but my listing of codes does not >indicate what the FF00 would point to. > >Of importance, I have a Supermac 2Meg upgrade that was installed in 1987, >and I am on my third power supply board (replaced 1 year ago). > >I am also having a real problem with the machine when trying to insert >a disk. If the machine has just been turned on, disk insertion (it normally >starts from an external HD) will cause a system bomb (ID=02, or sometimes >03?). Frequently, insertion will also cause a reset, periodically followed >by the infamous SadMac. Restarting, and then inserting a disk usually >results in normal performance. (but not always :-(...). > >My first suspicions of the cause(s) is the memory board. Since I have >been considering an upgrade, I want to insure that doing that will cure >the problem, and not be money down the drain (sure, I can use the memory >in another mac, but my other mac is a portable...). This sounds like a problem that Larry Pina told me about a year ago: In cases where there is insufficient power from the power supply, often a system error is caused. Here's the situation: Let's say your Mac starts normally from your external drive. You use it for a while, then throw a disk into your internal. This naturally enough causes the floppy motor to spin and a drain on the power supply. Normally, a power supply should deal with this drain OK, but if the supply is weak, *not set correctly!!!*, and you've got the additional drain from your SuperMac board, the power could fall enough to underpower the logic and Poof! system error time. As I remember, Larry actually was able to demonstrate this. Here's what I'd do, in order of importance/cost: 1) check the power supply - it should be *exactly* 5 volts! You can measure it from the middle plug in the harness that connects the logic board with the power supply (one slot is empty, count the slots-not the wires). Use a digital multimeter for best results. Please take proper precautions against the high voltage present in the area-if you have never worked on electronic equipment, find a friend who has. It's not hard, but there are safety rules which must be followed. You can set the voltage using a 99 cent TV alignment tool from Radio Shack. Don't buy the $5 package of tools, all you need is the ones in the 99cent package. Before setting the voltage, while the Mac is hooked up to the multimeter, try throwing a disk in the internal drive and watch what the voltage does. You know, so many Mac pluses just have the voltage set wrong. The worst offenders were the platinum macs, right from the factory. In an office with 8 pluses, the two worst were the newest platinums (one was at 4.6 volts!) Often, repair shops replacing power supplies and upgrades fail to reset the voltage correctly. 2) Since you've already blown three power supplies, its high time you upgraded the one you have and stop throwing money at your local Apple repairman. You can get a complete set of parts from SoftSolutions, with a soldering iron and the aforementioned multimeter, you can install the kit in a couple of hours, and probably never have to worry about power supply again. SoftSolutions (503) 461-1136. Complete instructions are in Larry's book "Macintosh Repair & Upgrade Secrets" most likely in your local mall. As you can see above, I know Larry, but I don't make any money on his book sales. As a further thought, you might want to measure the voltage (before you reset it) with the Supermac board on vs. with the board removed. This might give you an idea of the power that the board is drawing. Good luck, Owen Owen Hartnett omh@cs.brown.edu.CSNET Brown University Computer Science omh@cs.brown.edu uunet!brunix!omh "Don't wait up for me tonight because I won't be home for a month."