Re: Question about Sun Rem SCSI card

From: Luke Goembel <idylukewild_at_email.domain.hidden>
Date: Sun, 27 Jul 2008 09:32:43 -0700 (PDT)

Good to hear from you Ray!

Thanks for your advice about
care for the Lisa! I was wondering
about the 'power always on' feature
of the Lisa and had been unplugging
it from the first day I started
reviving mine.

Your advice to minimize the use of
the Lisa and to add cooling also
seems good.

Ray wrote:
> I don't know whether any thermal paste was used inside
> Lisas, I've not noticed any in mine - they're common inbetween
> CPU's and their heat but stock Lisas don't have heat sinks - I
> suspect the case would act as a heat sink, but there's no heat
> sink in the modern sense of the
> word, so probably there's no thermal paste either.
> (Perhaps the XLerator boards use them.)

By heat sinks, I specifically refer
to the sort of heat sinks used
on power transistors as described here:

Not that it's hugely important,
I'd like to point out where thermal
paste was used on my Lisa.
As far as I have been able to tell,
my video board is essentially the
same as that described in this schematic. apple/lisa/Lisa_Video_Board.pdf

Here are the heat-sinked components
on the video board: The link is to a photo posted on by a person who had a faulty Q5, one
of the two heat-sinked components on
the board. Another contributer to the
post mentions his U1 (24V regulator)
needed replacing. My U1 is what was
faulty and it evidently overheated
at some point. I am not sure that
'thermal paste drying out' was the
cause of the failure of the heat-sinked component, but the paste was dried
out and discolored on the failed
component on my video board. The
bolt that held the heat sink in
contact with the component also
appeared to be looser than I would
want to tighten such a bolt. Additionally, there was a gross over-application
of some blue compound (glue?) on the six video trim potentiometers. Upon
removal of one trim potentiometer
I saw migration of the glue into
the resistive surface. That rendered
the trim pot unadjustable.

I guess these are some quality
control issues to bring to
Apple's attention before they
produce more Lisa video boards ;)

Thanks for making your wonderful
website and the Lisa emulator!


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