NeXT cube problem fix

From: Mark Tapley <mtapley_at_swri.edu>
Date: Mon Jun 25 10:07:31 2001

All,
        I think I can finally report what was causing my intermittent NeXT
cube "unexpected kernel page fault" crashes. Up-time is now over 240 hours
and counting.
        The problems were heat, and bad ventilation. The short story is, I
had the fan reversed (to blow into the cube) and had a very leaky enclosure
as the first step on the cooling air path. This was due my installation of
a floppy drive looking out through an optical-drive-sized aperture in the
front of the cube.

        Clue for NeXT cube owners: seal up unused apertures and air leaks
in the front of the cube. The air needs to go into the drive bay, down into
the power supply, out into the motherboard bays, then out the bottom of the
machine.

        In my case, sealing apertures alone didn't do it - I ended up
putting the fan back to its original flow direction (exhausting from the
cube, so that the CPU board gets the cool air *first* as it is pulled in
from under the cube, rather than last as it goes out via the power supply).
I also sealed up the optical and floppy apertures completely, using blocks
of black foam rubber (which I'll pull temporarily in order to use the
drives as needed). This may eventually cause trouble with the optical or
floppy, YMMV and I don't have any long-term experience with it. I'm hoping
it will minimize dust build-up in the optical, which is the original
well-known reason for reversing the fan.
        Hope this is helpful, and many thanks to the list members that
helped me with hard drives, parts, etc. The "long story" of all the stuff I
tried and why I tried it is available on request, for the next few weeks at
any rate (until my WORN cranial storage system has purged the details....).
                                                                - Mark
Received on Mon Jun 25 2001 - 10:07:31 BST