August 28, 2005 on 4:38 pm | In Making | 2 Comments

On switch, reset switch, power light, hard disk light. Dull stuff…
but vital if you want to actually be able to turn your PC on and see if
it’s doing anything! The problem is that I didn’t want to us the cables
that came with the original case, and when I ordered new motherboard
pin connectors, the wrong ones came – spot the difference:

The
problem is that these don’t fit the motherboard pins – arg. However, I
remembered a cunning trick that I heard about. The case connectors are
all separated because they need to fit lots of different motherboards,
which tend to put their connector pins in different orders. However,
I’m only trying to work with one motherboard, so I could wire
everything up to a single big block and put it on the motherboard. To
do this, I took a spare IDC connector and ribbon cable from an unused
floppy drive:

Using a coping saw with a nice fine blade, I chopped the ends off so I had a socket exactly the right size for the motherboard:

Then,
using the manual for the motherboard, I worked out what pin was
connected to what wire, labeled the cable and soldered it to new push
switches / LEDs I’d bought earlier:

Finally I used some modeling epoxy glue to glue the now-smaller connector back together:

Happily
the resulting cable works perfectly and I can now make my mini-itx
board work! I just need to find places in the new Mac ‘case’ to put the
switches and lights. I think the lights will hide in old eject holes
for the floppy drive, and the switches will be around the back, where
they won’t ruin the lovely front of the mac.

August 28, 2005 on 3:43 pm | In Making | 2 Comments

After running the Mini-ITX motherboard for a little while sans case,
I decided that the fan was a little on the loud side – so I took a look
around for replacement quieter fans or better heatsink. After looking
around I found the Zalman Silent Motherboard Heatsink would do the job nicely:

To use with this I already had a nice big 92mm Zalman fan (ZM-F2) and also picked up a Fan Mate
speed controller to allow me to turn down that big fan to be as quiet
as possible. (The general rule of thumb with quiet cooling is that
bigger fans running at slower speed gives you the same airflow but with
less noise.)

To fit a new heatsink, first I had to VERY carefully
prise of the old heatsink. It is held on by two push-pins, and some
thermal gluey stuff. The pins can be carefully squeezed together with a
thin set of plyers and pushed back through to the other side of the
motherboard. Then, after heating up the heatsink by either running the
computer for a while or with a hair dryer, a small screwdriver is
placed between the heatsink and motherboard (NOT the cpu itself) and
rotated to gently pop it free.

After that, we have a CPU covered
in blank gunk. Happily Bobble had some surgical spirit which was
excellent to clean off the gunk, with the use of cotton buds to both
apply small amounts of spirit and wipe off the gunk. After that we have
a nice clean CPU:

First I lined up the pins in the
new heatsink, so they would fit the board. Then I had the fun task of
applying thermal grease to the CPU. It’s a white, sticky substance that
looks for all the world like Tipp-Ex (or White Out, or correcting
fluid, depending on what you know it as). That has to be applied
smoothly and evenly to the CPU – a bit of a fiddly job. Then I placed
the new heatsink on top, pushed the pints through to secure it, held it
in place for a while and finally left it overnight to set.

The
next day a test with benchmarking and ‘cpu burn in’ programs revealed
the CPU was running about 5 degrees cooler with the fan on minimum
power, and over 10 degrees cooler with the fan making quite a racket!
So that should help avoid overheating in the new case. The motherboard
also ran quite a bit cooler, no doubt due to increased airflow from the
big fan.

You will also notice in the photos that there is a big ATX Power Extender Cable
being used to separate the motherboard from the DC inverter board, this
is again to give more space and airflow to the motherboard. The DC
inverter definitely generates some extra heat that makes a difference
to the motherboard’s ambient temperature.

Suppliers used: QuietPC.com and Mini-ITX.com.