Monday, March 7, 2011

Homebrewn 1960's style nettop

The screen on my Atom N270-based Acer ZG5 netbook died and I decided to take it apart and put the guts in a different case. It gets used for daily browsing and some light torrenting and movie watching, driving a 1920x1080 display over VGA without issue. The case I used is one intended for storing photographic slides, made by the Smith-Victor company which I discovered still operates today. The dimensions are somewhere around 14" by 7" by 2" deep, big enough that the motherboard takes up about half the footprint. In keeping with the 1960's-ish audiovisual theme I added some 3/4" high rubber feet for clearance.

Using a dremel, I made cutouts for VGA, ethernet and one USB port. Not accessible without opening the case are the power button, audio jacks and the other two USB ports. The power brick is mounted internally and there's a cutout for the AC cord as well. The DC line is soldered directly to the motherboard's input, bypassing a dodgy section of cord that had been causing problems since before the screen broke. The motherboard rests on the battery at one end and the power brick at the other, both of which are conveniently around the same height. Unfortunately the battery is no longer recognized, which hasn't ended up being a big issue because the computer generally stays in one place.

I also had an idea that I would replace the stock hard drive with a 3.5" desktop drive, since there's plenty of unused space on the right hand side of the case. To that end I installed a power supply pulled from an old cd burner enclosure, and made another cutout for the power cord jack. I bought a molex to SATA power adapter to hook up the drive, but haven't got around yet to ordering a gender changer to allow plugging a SATA data cable to the motherboard. It would only be a 2 or 3 dollar part but I'd have to send away for it and at the moment I don't have a spare hard drive to use with it anyway. So, for the moment the cutout is just used for USB and audio cables. There's one 6" USB extension and one 4-port "squid" hub, an essential component since the keyboard, mouse and other devices are all over USB.

The mini-PCIe slot of the computer is not in use at the moment, as using it would require some alternate means of holding the card down. If you wanted to get fancy with the original wireless card, I guess you could wire up the internal antenna connectors to connect to standard RP-SMA connector antennas through additional holes in the case, but instead I have been using a USB adapter or wired ethernet. USB 3.0 or gigabit ethernet are other possibilities for the mini-PCIe slot but neither seem to be very affordable at the moment. I can understand that since adding either to a typical laptop would be impractical.
There remain some idiosyncrasies with the design (primarily that the case needs to be opened to use the power button etc.) but I'm pretty happy with it as a first attempt. I'd like to try to construct a similar-sized case from scratch out of aluminum or maybe copper or brass, for use with a mini-ITX motherboard, picoPSU,  and maybe a full-sized 3.5" hard drive. The pipe dream is to make a few to sell but we will see.