Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!uunet!visix!news
From: amanda@visix.com (Amanda Walker)
Newsgroups: comp.sys.mac.hardware
Subject: Re: mac IIsi + third party memory + apple nubus adapter = ?
Message-ID: <1991May9.052255.17457@visix.com>
Date: 9 May 91 05:22:55 GMT
References: <17544@burdvax.PRC.Unisys.COM>
Sender: news@visix.com
Organization: Visix Software Inc., Reston, VA
Lines: 34

In article <17544@burdvax.PRC.Unisys.COM> jjs@PRC.Unisys.COM (James
Solderitsch) writes:

   0.  What was the machine doing when it would shut itself down? -- in
       retrospect, it seems like it was protecting itself from some
       kind of short or overload.

Exactly.  If the switching frequency of the power supply drops below
a certain level (which would be caused by too heavy of a power draw),
the power supply will shut down.  I believe there is also a fuse, just
in case it doesn't shut down fast enough.

   1.  Guesses as to what went wrong: bad nubus adapter? bad motherboard?

Sounds to me like a short circuit in the NuBus adapter or connector.
Just to reassure you, my IIsi has exactly the configuration you are
trying to have (4MB of 3rd party memory and a NuBus adapter) and is
working just fine :).

If the same thing happens with a new NuBus adapter, I'd suspect the
expansion connector on the motherboard.

   Should I be wary of adding a 105 meg low-profile drive too?  That
   was going to be the next upgrade.

The low-power Conner one should be OK, but I'd check the power
requirements of anything else, especially if you plan to put a NuBus
board in (as opposed to just using the adapter for its 68882).

--
Amanda Walker						      amanda@visix.com
Visix Software Inc.					...!uunet!visix!amanda
-- 
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