Sunday, February 28, 2010

Assembling Juno: Screwdrivers and cablegami

Juno is my new computer. It's named after the asteroid, not the movie -- I saw a news item about the opposition of the asteroid Vesta, and thought that among the four major asteroids (Ceres, Vesta, Juno, Pallas) that I liked the name Juno best.

I wasn't planning on building a new computer for at least another six to ten months, but my three-year-old machine, tbroma (short for theobroma, "food of the gods," a reference to chocolate) had developed a quirk. Nine times out of ten, when turning the computer on, it would have a) forgotten what time it was, and b) disabled the network interface (no Internet). This fault is typical of a weak CMOS battery, but I changed it twice and the problem persisted. I would have to intercept each boot to fix the settings in the BIOS, so it was time to accelerate my schedule.

I won't bore you with parts selection; as always, I found the Silent PC Review web site invaluable. Joan will tell you that I peruse the forums there almost every day. My goal was faster, smaller, and cooler (less electricity) than tbroma. With three years of technology advances, I ought to be able to do all three.

Here's a view partway through the assembly process. The CPU heatsink and fan are mounted on the motherboard, front fan attached, and cables from the front ports and status lights plugged in. A 2.5" (laptop style), 500GB hard drive is attached to a plastic frame (slot rafter). The rafter is supposed to snap into the orange expansion slot at the bottom of the board, but that would put the drive and plastic tabs where they blocked parts of the motherboard. (The rafter is cut to 60% of its original size because that's all I needed.)
The two plastic gadgets at the front and back (not permanently mounted yet) are fan controllers that let me dial the fans up and down in speed, to get the best balance of cooling and quietness.

The tray for the slim optical drive blocks a lot of the case from the top, so it was usually kept to one side, and the fit checked now and then.
The heatsink is a mid-size aftermarket model. Here we see that it clears the northbridge heatsink and the memory cards, but not by a whole lot. Install the memory cards first!
Some CPU heatsinks mount to the motherboard with a push-pin system (similar to the one you see on the black northbridge heatsink above) that many find awkward. This one attaches with a nice, solid backplate and screws. You add the screws that are going to pass through the motherboard to the clips (shown below), screw the clips onto the heatsink, and then fasten from the back side of the motherboard; even though there are more steps involved than with pushpins, you're never required to do difficult things in tiny spaces. The screw shown below actually threads through the hole in the clip, so it's solidly attached when you're handling the clip.
To gain efficiency and room for the larger heatsink/fan assembly, I replaced the power supply that came with the computer case with a picoPSU. The AC-DC conversion is done in an external brick, just like when plugging a laptop into the wall, and a small voltage converter plugs into the power socket on the motherboard.
Here I've circled the port on the picoPSU that lets you plug in an additional cable set. Unfortunately, it points straight back at the blue memory heatsinks, only 1mm or 2mm away. I could plug the cable set into this port, but the cables visibly pushed against the memory and back against the picoPSU, so I dropped that approach and got a cable splitter to turn one SATA power cable into two.

Here's a look into the top as I transitioned into the cablegami stage. The fan controllers are permanently mounted, and the CPU power cable snakes around the heatsink (required an extension!) The splitter cable is in evidence at the edge of the heatsink, and the 2.5" hard drive has its data and power cables plugged in. But nothing is tidy(ish) yet.
Just to emphasize the complications from the optical drive, here's a photo. Look at the length of the optical drive power and data cables -- they're intended for much larger cases. I'm using a case for mini ITX motherboards -- smaller than a micro-ATX motherboard, which is smaller than standard ATX. You'll see exterior shots later of my earlier, micro-ATX case and this mini ITX case.
Here's a shot of the left side after some cablegami efforts. The Y-splitter, power cable headed for the picoPSU, one of the optic-drive cables, and the CPU power cable are all tucked in the 1" gap between the plastic raft and the edge of the case. Similarly, the black data cable to the second storage device, an SSD (solid-state drive, using flash memory) takes advantage of that gap.
Looking at it from the right side, we see that the airspace in front of the fan is more or less clear of cable clutter. The small wires are below the airpath. (The SSD is in the small bay hanging from the bottom of the optic drive tray.)
Here, the case is buttoned up. Black mesh (window screen material) is backing the vented areas to protect against dropped little screws and other disasters. I also used it to cover the hole where the original power supply was installed. Black construction paper (think scrapbooking) blocks part of the left vent to match the right vent. I don't have a high-powered graphics card throwing off heat on the left side, so it's best to focus the airflow where it's going to be needed. (The color differences are exaggerated by the photo flash. It's a decent match in ordinary light.)
Here is juno positioned next to tbroma, still in use. My computing philosophy now emphasizes compactness in all things except monitors!
Now it's time to power juno up, see what happens, install Ubuntu 9.10, and move my files over.

No comments:

Post a Comment