• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Macintosh SE system errors

larsove

Active member
I just recapped one of my Macintosh SE's logic board and it has started to show some errors. Mainly System Error 03 and 10. They might occur at random, or when opening a folder, or shutting down the machine. I have yet to recap the analog board but will do that asap.
The SE is running its original HD and has 4mb of ram. Is there a program that can test the macs system and ram?

I have backed up the content on the HD and have an external blueSCSI that I am planning on using as the main HD since the old one is quite noisy,

cheers!

-LarsO
 

dochilli

Well-known member
Sad mac error code:
The RAM test failed while testing bank B after passing the chunk tested for code $0002. The Z field indicates which bits failed as in code $0002.
AA=8 bit mask for bits 31-24
BB=8 bit mask for bits 23-16
CC=8 bit mask for bits 15-8
DD=8 bit mask for bits 7-0
Should be a problem with the RAM. Reseat the RAM or use a known good. Could be bit 5.
 

larsove

Active member
Sad mac error code:
The RAM test failed while testing bank B after passing the chunk tested for code $0002. The Z field indicates which bits failed as in code $0002.
AA=8 bit mask for bits 31-24
BB=8 bit mask for bits 23-16
CC=8 bit mask for bits 15-8
DD=8 bit mask for bits 7-0
Should be a problem with the RAM. Reseat the RAM or use a known good. Could be bit 5.
Thank you for your reply.
It's not a sad mac error, It's a 'MacBomb' error, so number 03 = 3 Illegal Instruction, and number 10 = 10 Line 1111 Trap.
Trying to figure out what causes these system crashes. If there is a faulty ram chip, is there software to test and check what address line is faulty.
 

larsove

Active member
Like this:
bomb.gif


Maybe I'll just start off with a new clean install on my blueSCSI. I've taken backups of the original HD so I don't really need it.
 

larsove

Active member
Update on this one:
I have recapped the Analog board, logic board and PSU. Most of the errors are gone, but the SE still freezes. It usually happens after some time and the error is now just a blinking empty error screen - and the SE freezes.

I ran Apple Personal Diagnostics and it passed all tests- both short and long RAM-test. anyone have suggestions?
 

joshc

Well-known member
Try with different RAM. Also clean the RAM contacts and the RAM slots with contact cleaner.
 

larsove

Active member
Try with different RAM. Also clean the RAM contacts and the RAM slots with contact cleaner.
I’ll swap the chips with known working ones from one of my other SE/PLUS.
Already cleaned ram slots, but I’ll do it again for good measure.

This really makes me question the RAM-test in Apple personal diagnostics….
 

larsove

Active member
Just another thought: are the compact macs picky about their type of DRAM/SIMMs? The ones I have installed are Samsung branded with three chips on each module. I’ll find chip numbers etc tomorrow. But Maybe they are causing timing issues that makes the SE crash?
 

larsove

Active member
This SE keeps throwing new errors at me. New one to day, after cleaning RAM chips and SIMM sockets.
Works well for a while and while Ideling it freezes. and then this:IMG_8878.jpeg
 

dochilli

Well-known member
Did you measure the voltages at the floppy port? Should be 5 and 12 volt.
Did you clean and reseat the ROM?
 

larsove

Active member
Did you measure the voltages at the floppy port? Should be 5 and 12 volt.
Did you clean and reseat the ROM?
Yes, it measures 5.082, 12,73, -11.47 - no HD load so from what I’ve heard now these are values to be expected. I’ve cleaned and reseat ROM chips and sockets. I’ve also cleaned ram sockets and ram pads, and tried 8 different 1mb ram simms.
 

dochilli

Well-known member
Voltages are ok, perhaps you could measure with an oszilloscop, if they are stable? But when you recapped the AB, they should be stable.
Are there chips that are getting hot? Could be a temperature problem when the SE freezes after some time.
 

larsove

Active member
Voltages are ok, perhaps you could measure with an oszilloscop, if they are stable? But when you recapped the AB, they should be stable.
Are there chips that are getting hot? Could be a temperature problem when the SE freezes after some time.
I haven't figured out a way to check if chips are getting hot(touching) as access to the motherboard while the computer is on is almost impossible. Do you have a good way of doing this?

I do have an oscilloscope, so maybe it's time to learn how to use it properly.
This is one of the early SEs with the squirrel fan. The sound of the fan does change, it's not as constant as with the regular fans. But I guess that is just a result of the design of the fan.
 

bibilit

Well-known member
I haven't figured out a way to check if chips are getting hot(touching) as access to the motherboard while the computer is on is almost impossible. Do you have a good way of doing this ?
The board can be left flat, using a long ATX cable image_2023-04-26_163028401.png
 

larsove

Active member
After the last crash, as seen in the video, I was quite confident it was a broken solder joint issue. I don't have a microscope and upon first inspection before recapping the analog board the joints looked fine to my eyes. But as I've taken the connectors on and off to insert new ram chips and recap etc new problems just came at me. First it was address errors, random freezes, then vertical bars, then the scrabled/distortion screen. So I've now reflown every solider joint on the analog board, and the atx-connector on the logic board. I also noticed an oscillation in the fan - that i first thought came from an unstable PSU - but it kept on going after a recap. and voltage readings were fine. I believe the small vibrations the squirrel cage fan sends across the analog board makes the SE crash because of the (micro) cracks in the solder joints. After removing old and adding new solder the the analog board that oscillation has now stopped - and the squirrel cage fan is not that noisy anymore. Still want to swap it out tho.
The machine has been running stable for about 20 minutes now. that is about 17 minutes longer than average for this machine. fingers crossed that it's now fixed and running stable!
 
Top