I have mostly completed converting a Shuttle G5 case (SD32G5) into a modern AM3 mini-ITX system. Only do this if you really love the look of your Shuttle, otherwise it is completely impractical. The Silverstone SG05/SG06 is only slightly bigger than the Shuttle G5 case, and for an ITX system, it is superior in every way.
The main steps are:
- Remove the existing motherboard standoffs.
- Drill new holes for the new motherboard standoffs.
- Enlarge the rear I/O opening. Only one PCI slot will be usable.
- (Optional) Drill holes and cut openings for a 120mm fan instead of the stock 92mm fan.
Pictures without drive bay and video card:


Picture of rear, after installing 120mm fan, cutting the fan grill, and enlarging the rear I/O opening:

Front internal view with video card installed:

Drive cage just barely fits without any mods:

Components used:
MINIX 6150SE-UC3 motherboard (budget AM3 board, uses full-size DIMMs)
Scythe Samurai ZZ CPU cooler (flipped fan to blow upwards)
120mm Globe Golf Fan as case fan (from Silverstone SG05)
Mushkin Silverline DDR3 RAM (has a very low heatsink)
Seasonic SS-250SU PSU (stock Shuttle PC40 would also work)
Nvidia GT240 single slot video card
I've also filled up the drive cage with a 5.25" DVD-RW optical drive and two hard drives (one SSD and one HDD).
The Shuttle front panel USB/audio uses a proprietary connector and I do not know how to adapt it. I think the two options are:
1) Get a front panel USB/audio board from another computer case, and cut new openings to fit; or
2) Get a 3.5" bay with front panel I/O.
I posted my build log in this thread on SPCR, so check that for more details.
The main steps are:
- Remove the existing motherboard standoffs.
- Drill new holes for the new motherboard standoffs.
- Enlarge the rear I/O opening. Only one PCI slot will be usable.
- (Optional) Drill holes and cut openings for a 120mm fan instead of the stock 92mm fan.
Pictures without drive bay and video card:


Picture of rear, after installing 120mm fan, cutting the fan grill, and enlarging the rear I/O opening:

Front internal view with video card installed:

Drive cage just barely fits without any mods:

Components used:
MINIX 6150SE-UC3 motherboard (budget AM3 board, uses full-size DIMMs)
Scythe Samurai ZZ CPU cooler (flipped fan to blow upwards)
120mm Globe Golf Fan as case fan (from Silverstone SG05)
Mushkin Silverline DDR3 RAM (has a very low heatsink)
Seasonic SS-250SU PSU (stock Shuttle PC40 would also work)
Nvidia GT240 single slot video card
I've also filled up the drive cage with a 5.25" DVD-RW optical drive and two hard drives (one SSD and one HDD).
The Shuttle front panel USB/audio uses a proprietary connector and I do not know how to adapt it. I think the two options are:
1) Get a front panel USB/audio board from another computer case, and cut new openings to fit; or
2) Get a 3.5" bay with front panel I/O.
I posted my build log in this thread on SPCR, so check that for more details.