Macintosh LC III: System error on fresh startup disk.

[macgeek417]

I just wrote a System 7.5 NAD floppy to complete the OS 8 on LC III hack, anjd was gretted with "Sorry, a system error occurred. bus error to temoporarly turn off" blah blah blah... error. any clues what bus is getting an error?

 

[Gil]

As I've said in another thread here recently, I used to get this a lot with an LC 575...washing the motherboard took care of the problem. It could be cap related, or any number of things. I have no way of knowing whether washing the logic board solved the problem, but a little anecdotal advice can never hurt.

 

[macgeek417]

You fixed a bus error by washing the mobo? how would I go about washing the mobo?

 

[JRL]

Just try a different boot disk (i.e SuperBooter 7.5)

 

[macgeek417]

the 7.5 nad worked fine before. the problem is NONE of my bootdisks are working: an old 7.5nad (system error) the new one (bus error) the 7.6 disk tools disk (happy mac, then back to blinking ? mark.

i'll try removing the ethernet card and ram.

 

[macgeek417]

...and no luck. I'll try the superbooter.

 

[macgeek417]

...and I can't find a working link. anyone wanna volunteer a DC42 or RAW floppy of it?

 

[JRL]

or just use the LC III System 7.1 disk tools disk (which is on the Legacy CD)

if it doesn't work, I'll PM/email you a SuperBooter image.

 

[macgeek417]

*looks through Legacy CD*

 

[macgeek417]

OK, before I try another boot disk, should I just wash the mobo? the 7.5NAD worked fine before, and now none of my boot disks work.

 

[porter]

Interesting, years ago when I did a lot of hardware, one would track down problems with voltmeters, continuity testers, oscilloscopes and logic analysers. Now people seriously suggest putting things in the dish washer. If only all sins could be so easily washed away.

 

[JRL]

OK, before I try another boot disk, should I just wash the mobo? the 7.5NAD worked fine before, and now none of my boot disks work.

Nothing's wrong with making a fresh (different) boot disk with a new floppy just to make sure.

 

[macgeek417]

how do I go about taking out the mobo and washing it?

 

[JRL]

You know it's very possible that the disk just got corrupted, especially if it wasn't new.

If you don't hear a whistling sound from the speaker or unusually weak sound, then it's not your caps.

 

[macgeek417]

it was a brand new disk

how do i get out the mobo and wash it?

 

[porter]

it was a brand new diskhow do i get out the mobo and wash it?

1. Open the case.

2. detach cables

3. unclip plastic clips

4. put in dishwasher

Apparently.

Note, washing a motherboard is not the same as re-capping.

 

[JRL]

it was a brand new diskhow do i get out the mobo and wash it?

Before you begin, remove

the following:

•Top cover

•Fan

Review the ESD

precautions in Bulletins/

Safety.

Logic Board

Take Apart Logic Board - 19

1 Disconnect the following

cable connectors from

the logic board:

•Hard drive power

cable

•Hard drive data cable

•Floppy drive cable

•Power supply cable

•Fan cable (LC II/III/

LC 475 and Quadra

605)

•Speaker cable (LC II/

III/LC 475 and

Quadra 605)

2 Remove the expansion

card (if installed).

Caution:

In the next step,

be sure the power on/off

button clears the rear panel

before you remove the logic

board. While lifting the

board, do not touch any

components or connectors on

the back of the logic board.

(The oil from your skin can

harm the connectors.)

Take Apart Logic Board - 21

3 Using your forefingers,

spread the two latches

that secure the logic

board to the bottom case.

At the same time, using

your right thumb, push

on the expansion

connector and slide the

logic board toward the

front of the case.

Take out the logic board and wash in cold-slightly warm water with a little soap in a dishwasher or bathtub.

 

[Strimkind]

I just wrote a System 7.5 NAD floppy to complete the OS 8 on LC III hack, anjd was gretted with "Sorry, a system error occurred. bus error to temoporarly turn off" blah blah blah... error. any clues what bus is getting an error?

This may seem simple but is everything connected properly to the logic board (HD cable, RAM, etc)? Have you tried a different stick of RAM?

 

[macgeek417]

The LC III has logicboard RAM. i removed my 32MB of extra ram and the ethernet card, but no luck

im gonna try a 7.1 disk tools disk.