Subject: Re: problem booting on IIsi
To: Brahm Windeler <rahm@engin.umich.edu>
From: Bruce Harada <harada@ja2.so-net.ne.jp>
List: port-mac68k
Date: 06/03/1998 06:58:21
At 15:17 98.6.2 -0400, Brahm Windeler wrote:
>as an update to my last message, i've found that the trick was in
>unplugging the computer before taking the cover off.  leaving the computer
>unplugged for about 10-15 seconds allows me to get past that point
>mentioned in my previous messages.  i've also found that zapping the pram
>does the same thing.  after either of these has been done, my computer
>begins the normal mac boot sequence...start-up noise sounds, pointer shows
>up on screen & happy mac appears in the center...then it starts over; the
>start-up noise sounds again but the sequence goes through the whole way. 
>i don't know exactly what's going on, but it works.  upon further
>inspection, it looks like the internal battery is dead.  i'm going to see
>if i can find a replacement soon.  i'm not sure if this will help, but
>it's something that should be done anyway. 

If you haven't already, you might want to try reinstalling the Mac-side
system from scratch and then clearing PRAM on the next startup.

I had a Mac with a dead battery that would start up fine the first time
after unplugging it, but after resetting, would stop partway through the
MacOS boot sequence. After digging around a bit, it seems that what was
happening was that:

1. Unplugging it cleared the PRAM because of the dead battery.
2. The System file was damaged enough to put junk into the PRAM.
3. Restarting without unplugging caused it to try and make sense of the
PRAM contents, making it freeze.
4. Clearing the PRAM would fix it, but the damaged System file would just
junk the PRAM again.
5. Replacing the system would work once, but the junk in PRAM would damage
the System file again in the same way.
6. And so on in an infinite loop.

I eventually got it working by installing a new system, and after hitting
the restart from the installer, immediately clearing the PRAM on startup.
It's probably not something that happens very often, but it's a pain in the
ass to figure out.


Bruce Harada




**********************************
*          Bruce Harada          *
*                                *
*         bruce@ask.or.jp        *
**********************************