SE/30 freezes on floppy initialization (every time)

[man4mac]

Recently got an SE/30 and restored it to good working order. It was rockin the simasi, so I recaped it, and that fixed that. The floppy drive wasn't working so I performed the full cleaning/lubing and that's back to tip top shape. Then I installed a fresh OS 7.1. All is good...

Except when I try to initialize a floppy it freezes the OS 100% of the time. I've received the following in seemingly random order:

Error 11

No FPU

No Error just frozen screen

It is able to read/write to the floppy just fine. Any guesses or ideas?

 

[man4mac]

I'm guessing this might be tracked back to the SWIM chip and some of the traces going there. But honestly, I'm shooting in the dark.

I do have an SE Superdrive as well, are the floppy drives from those machines interchangeable with the one in the SE/30? If so I could swap them and check to see if I'm dealing with a hardware issue on the drive itself or on the logic board somewhere. Any suggestions would be very welcome.

 

[Themk]

Yes, the floppy drives are interchangeable.

 

[man4mac]

Good to know I can swap those drives out. I haven't had a chance to do it yet, but I just had another interesting floppy mishap with this machine I thought I would post in case it gives someone a clue. I tried to boot the machine off a 6.0.8 800k floppy, and it totally wigs out. The "Welcome to Macintosh" screen begins flashing and the boot never progresses. Check out the attached video. You may or may not hear it in the video but there is a slight "clicking" sound that starts when the screen starts going wonky.

Any clues or problem-solving tips at all would be helpful.

se30-floppy-fail.mov

 

[Themk]

Flashing "welcome to Macintosh" is due to floppy read error. The clicking is probably your floppy drive. Clean the R/W heads, and lubricate everything in the floppy drive.Read this wiki page on cleaning and lubrication

 

[man4mac]

Right. Except like I said in the OP I just did a full clean and relube (which got it working again).

 

[techknight]

Depends on how heavily used that floppy drive actually is. If someone has used the crap out of it, the head gap could be worn beyond usable condition. 

 

[man4mac]

Is there anyway for a mere mortal to test/repair an out of tollerance head gap?

 

[Themk]

repair it? Not likely

On a slightly brighter note, you might just still have garbage on the heads which needs more cleaning to remove; worth a check!

 

[man4mac]

Fair enough. It's worth a shot, it was in bad condition. Still, 2 questions:

1. If the heads were bad wouldn't I have read/write issues? I installed a full OS (5 floppies worth), and did some light writing with no issues.

2. If there were head issues wouldn't I just get a "bad disk" or some such error (as I have on other machines) rather than a full system crash?

 

[Johnnya101]

1. Yes.

2. Yes.

It's not a head issue. It's something with its controller. You can always just buy one and try it out. Or maybe it's a chip?

If you were having head issues you would not be able to read anything, but you would be able to initialize (But would fail verification.

I would try switching out drives. I don't think you did that? If it does not make a difference, then move on to reinstalling the os. If that doesn't work it's something on the logic board.

 

[Themk]

Definitely try your other drive, that way you know if its a logic board (and by extension possibly controller) issue, or a drive issue.

edit: Actually, you probably have a broken trace somewhere; got to go get the schematics (I like the BOMARC ones), and the multi meter and check it out.

 

[man4mac]

I would try switching out drives. If it does not make a difference, then move on to reinstalling the os. If that doesn't work it's something on the logic board.

Yeah, grrr. Unfortunately, this is the 3rd OS I've tried with similar results.

Definitely try your other drive, that way you know if its a logic board (and by extension possibly controller) issue, or a drive issue.

edit: Actually, you probably have a broken trace somewhere; got to go get the schematics (I like the BOMARC ones), and the multi meter and check it out.

Shoot haha. I'll try swapping drives tonight or tomorrow just in case, but what made you start thinking broken trace?

 

[Johnnya101]

Probably because the system is fine until you call for an initialization... I'm not a trace guy (yet) so I'm not sure if that's right.

 

[jack]

[...] go get the schematics (I like the BOMARC ones) [...]

Are the BOMARC schematics still floating around anywhere on the internet anymore?

 

[man4mac]

Probably because the system is fine until you call for an initialization... I'm not a trace guy (yet) so I'm not sure if that's right.

Right. The floppy drive seems in great condition, except for initializing a new disk and now the 6.0.8 boot from floppy (see above video if you haven't yet).

Are the BOMARC schematics still floating around anywhere on the internet anymore?

Yeah I have a copy of BOMARC pretty sure you can get them here: https://www.macintoshrepository.org/875-macintosh-se-30-schematics-and-repair

 

[Themk]

Yup those are the right links to the BOMARC schematics!

Probably because the system is fine until you call for an initialization... I'm not a trace guy (yet) so I'm not sure if that's right.

Here is why I thought it could be a trace issue, though this doesn't explain why the drive works for other things other than booting an 800K disk and formatting a disk.

Error 11 is a referred to as a hardware error.

"No FPU" is probably due to a bus error of sorts

The freezing is what is really tipping me off. My SE/30 board freezes every time you try to use the SCC, and it freezes because I have a broken trace somewhere.

 

[man4mac]

Ok, so here's another update. I finally got around to swapping drives last night, just to realize that the quantum drive in my SE/30 and the quantum drive in my SE had both decided to start having stuck heads at the same time. So niether would boot. Still I figured I could at least throw in the 6.0.8 floppy I've used before and test if it was able to boot on the SE/30 with the new drive. No joy.

Defeated, I decided to pull out a third Mac SE (not a superdrive), with a known good drive, that has booted many times from this exact 6.0.8 floppy, just to make sure the floppy was still good. lo and behold. The floppy was wouldn't boot on that mac either. So now I've got too many variables. Here's what I know: the SE/30 freezes when initializing a floppy. haha. no progress.

And basically due to a bad boot floppy and 2 bad quantum drives...I'm stuck at the moment. I'm going to try and repair a quantum drive and create another boot floppy. Fingers I'll have more soon.