On Thu, Nov 04, 1999 at 08:48:40AM -0600, Joe wrote:
> On Wed, 3 Nov 1999, Wilko Bulte wrote:
> 
> > As Joe wrote ...
> > > On Wed, 3 Nov 1999, Jan-Hinrich Fessel wrote:
> > > 
> > > > In message <199911022327.PAA12562@random.teraflop.com>you write:
> > > > nothing that really relates to this message...
> > > > 
> > > > I just wanted to know what Crystal to put on the PC164 MLB whit a 500MHz CPU 
> > > > and what combination of IRQ-Jumpers is the correct one.
> > > > 
> > > > My board just came in with a set of Crystals (up to 50.00, 36.6 std. 
> > > > installed) and IRQ2 jumpered.
> > > > 
> > > > Gruesse
> > > >        Oskar
> > > 
> > > You will want to use the 50.00 MHz crystal and I think that you want the
> > > jumpers to be off. You can the latest documentation for that board at:
> > > 
> > > http://ftp.digital.com/pub/Digital/info/semiconductor/literature/archives.html
> > > 
> > > It even tells you how much torque to put on the heaksink nuts. :)
> > 
> > Which is not just to be difficult. I know that in the DEC ^H^H^H Compaq
> > repair facilities they use a torque wrench to avoid overtightening or
> > warping the CPU metal plate. 
> > 
> > Wilko
> > -- 
> 
> Yes, but most people don't realize that at 20in-lbs you can torque it with
> your hands. If I only could reach the nuts with my fingers. :)

Yes, but then you might not get the right torque to compress the Grafoil
gasket correctly, and heat transfer from the processor to the sink might be
uneven, leading to premature CPU failure.

Of course, lots of people touch the gasket with their bare fingers, too,
and that's *definitely* a bad thing.  Yet I haven't heard of their CPUs
failing yet.  YMMV; the tool wasn't so expensive (try McMaster-Carr, *not*
Jensen, like I did) and since I was assembling 30-odd boards at once it
was well worth it for the peace of mind.

-- 
Thor Lancelot Simon	                                      tls@rek.tjls.com
	"And where do all these highways go, now that we are free?"