This
is the original case and hardware I started with, I eventually bought
many more small items to complete the mod. First picture shows
everything, in the second picture the hardware is stacked up, next is
the iMac case, fourth picture is the Samsung 151v LCD, and finally are
some miscellaneous parts from the iMac. I did want the option of
actually being able to play games on this machine, so I decided upon a
matx motherboard with an agp slot. This ended up being quite a hunt
finding one, but I did finally get my hands on one.

Hardware specs:

• PIII 1Ghz
• Intel matx motherboard
• 512 MB pc133 ram
• GeForce 2 MX-400
• 30 GB HDD
• 24x CD-ROM
• 350 w PSU
• 15 " LCD
  

At
first I thought a crt would be able to fit in the case but after
testing this I found out that it was out of the question, I would need
an lcd. After some searching around, I found a Samsung 151v for $200
that I decided to purchase. To be able to mount the lcd inside the iMac
case I would need to take the lcd out of its black plastic shell. After
a few easy screws it was out, it is now a bare lcd.

I
decided that a piece of acrylic in front of the lcd would be a good
idea to protect it from dust, scratches, and fingerprints. I dremeled
notches in the acrylic in association with the inside of the iMac case.
When I test fitted the lcd I found out that many of the small plastic
support pieces would have to be removed to create sufficient room for
the lcd. After I had the acrylic and the lcd mounted inside the front
frame I used hot glue to secure the acrylic to the case. Looking from
the front there is a gap around the perimeter of the monitor frame.
This is because the original crt has not flat, and the lcd is. To fix
this I used grey silicon caulking and filled in the gaps. Next I used
clear silicon to create a smooth finish. To mount the lcd and keep it
in place I used 1" wide aluminum pieces and cut them to length. The
holes used for the old crt were perfect to secure the aluminum. The
controls for the lcd were attached with double sided tape to the top of
the lcd.

The
CD-ROM drive from the iMac needed a little modding to work with a
regular IDE connection. I soldered some wire onto two leads in the back
of the drive that were labeled 5v, and ground; the wires were then
connected into a molex connector. The plug on the back has 50 pins,
after some reaseach I found that the first 40 pins are just normal IDE.
Since the cable is only 40 pins, and the cd-rom is 50, I sanded the end
of a connector on the cable. This prevents bending of the pins when the
cable is inserted into the drive. The drive is a slot loading, I did
search around for other options, but using the original drive from the
iMac ended up being the best option.

When
I first disassembled the iMac there was a mounting bracket that held
the cd-rom and hard drive in place. Somehow I misplaced this part, so I
had to create my own. I used the same aluminum material that holds the
lcd in place. To shape the bracket I clamped it in a vice and used a
rubber mallet to create the bends. Then I drilled two holes for screws.
The cd-rom drive and hard drive are shown mounted in place in the third
picture.

I
wanted to make the computer as clean as possible, this means hiding any
unnecessary wires. I decided to mount the power supply underneath and
out of view. I was rather lucky as there was just barely enough room
for the psu to fit without having to make any extra cuts. I drilled
four holes in the metal frame and stuck a piece of foam between the
power supply pcb and the metal. I then used fan screws to hold
everything in place.

The
iMac did not have any active cooling, but since I was going to be
running faster components I felt it would be necessary. After measuring
I found that nothing larger than 60mm would fit. So I found three spots
on the bottom with decent ventilation holes and cut out 60mm holes for
the three fans. Another goal I had was too keep the computer rather
quiet. Also because about 50% of the airflow would be blocked due to
the plastic casing, I decided to run the fans at 7v. I connected the
wires to a molex, positive to 12v and ground to 5v, creating 7v. At
this speed the fans are almost silent.

The
first test mount of the motherboard, everything looks to be fitting
fine. To mount the motherboard I drilled holes into the middle metal
frame and screwed standoffs in. Then I used some hot glue to secure
them in place since the holes I drilled were less than perfect.

To
keep the stock look I wanted to use the I/O panel from the iMac for the
new mod. Two items I would not be using however is the modem and
firewire. For the USB and Cat5 I made short extension cables that were
just the right length. To cover up the modem and firewire ports I cut
small pieces of acrylic to size and used grey spray paint on the back
side to give it a close match to the original iMac gray color. But I
did not want the space to just go to waste so I used the two firewire
ports for toggle switches. One is for a 4" cold cathode, the second
switch is to turn off the speakers for when I use headphones. Not
pictured however is what I created with the modem port. I drilled a
1/4" hole and mounted a pushbutton switch for the power supply.

Every
part of the iMac would still be functional when the iPC is complete.
The front power button is the motherboard power switch, and I changed
the green/orange led to a blue one. I used the original microphone on
the top of the iMac, as well as the speakers. I added RCA plugs to the
speakers in case I ever need to easily disconnect them. The last
picture shows an audio cable that supplies many parts. It plugs into
the motherboard sound port, then it goes to the I/O panel where it has
a port for headphones, as well as a switch for the speakers. Next it
powers the main speakers, and finally the front two headphone ports.
This cable took quite a while to figure out how to wire it and the
actual construction of it.

The
original internal power plug is also being used. I used hot glue once
again to secure the plug to the inside of the plastic frame. A black
project box was used to split the AC power to the psu and the lcd. I
had hoped to be able to mount this out of view but that did not work
out so it ended up being on the upper level next to the motherboard.

Finally,
construction. I cut every wire that was not going to be needed. Space
was very limited in the bottom of the iPC. I folded, wrapped, and tied
all the wires to create as much free space as possible for air cooling.
The bottom of the iPC is on and screwed down tight. The third picture
shows the lower half of the iPC mounted inside the plastic case, ready
for mounting of the motherboard.

Almost
complete, I am making the final assembly and putting the plastic case
together. I had quite a bit of trouble with the lcd cable. I did not
realize it at first, but I mounted the motherboard so there was only
about one inch of space between the video card vga port and the side of
the case. The original cable did not fit, no matter how hard I tried to
make it. I had to either buy a cable or create my own. After searching
around I found out that the cable needed costs about $50, way more than
I could afford. I had to make my own. I bought 2 15pin d-sub connectors
and used cat5 cable to create the cable. After a long time working I
got it finished, and it works! The last item installed into the case is
a 4" white cold cathode, this gives the case a nice glow but is also no
to flashy.The second picture shows the iPC just after I completed
building it, and my first time powering it up. Amazingly everything
works flawlessly.