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Macintosh Portable - unable to boot from floppy
Posted by: 80sboy on 2020-03-28 00:24:54
Greetings - well I figured with all the extra time right now from being home, I would attack my portable backlit model - 

  Removed all the caps, cleaned all the gunk with IPA< recapped - 

New 6V battery and new 9V battery - 

 Powers right now, nice bright backlit screen, but it will not boot from floppy, or hard drive which I assume the hard drive is just dead - but the floppy - oh boy - 

I tried another floppy from another non-backlit model - won't load any floppies, system 7 etc - just gives a floppy icon with an X through it - then I discovered I actually have a BMOW floppy emu!

Hooked that up and got excited for a minute when the happy face icon appeared, only to be quickly replaced by, yep, you guessed it, floppy icon with an X through it - tried many different images System 6, System 7 - etc - 

 from what I can gather it  is more than likely the SWIM chip? Is there anything I can do to test this? I have another backlit board, but it's missing a few chips, a couple voltage regulators, etc and I don't really want to spend the time recapping another board right now, that took longer than I was hoping, and I'm very bummed that its not up and running now - any and all help would be greatly appreciated - 

Thomas
Posted by: 80sboy on 2020-03-28 12:10:49
OK - pulled the board and powered it up, and the SWIM chip does not get warm or hot - I've tried booting off floppy emu in HD20 mode, nothing - 

  Not sure what to do next, I nave another backlit board I'm going to recap and hope for the best - 

@techknight are you still taking boards for repair? If I recap this backup board and it works, could I send you this board that's not booting from floppy?

thomas
Posted by: LaPorta on 2020-03-28 12:26:07
Could it possibly be a bad filter? If cap stuff got on the filter, it can possibly cause weird floppy issues. Happened to me on an SE once with battery explosion.
Posted by: 80sboy on 2020-03-28 12:51:37
Whats the filter? 
Posted by: 80sboy on 2020-03-29 14:01:18
Update, installed a SCSI2sd I had from an SE/30 and it powers up! Boots great from SCSI, but neither the floppy or floppy emu work. When I use floppy emu I get a disk error, do you want to initialize this disk etc and then it will fail. If I keep the internal floppy hooked up the system crashes on boot. So I’m assuming that it’s possibly the swim chip, is there a source for these?

  Happy this is at least working now, pictures soon!
Posted by: mattsoft on 2020-04-04 19:21:53
These Macs are particularly finicky and difficult. I'll be starting a recap of a 5120 tomorrow. Removed all the caps today and cleaned everything. What a mess! Wish me luck. 🙂

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