The redesigned, slimmer 21-inch iMac has gone on sale on the Web and at Apple stores, and Japanese Apple enthusiast site Kodawarisan has what appears to be the Web's first teardown of the aluminum all-in-one.

One big question we've had since the device was announced is how to crack its shell open and get at its innards. I don't read Japanese, but Google Translate does, and according to the site, the new form factor can be opened with suction cups, just like the old one.

The new model looks different inside from its predecessor—in fact, despite its thinner bezel, it's actually much roomier with the display off than before.

There are antennae mounted around the edges of the bezel (they're the golden-colored, vaguely razor-blade-looking things); they appear to be Wi-Fi. Previous iMacs used the front plastic Apple logo as the antenna window.

The logic board (Apple's name for its motherboard) appears to contain both the Ivy Bridge i5 and the GPU, unlike previous iMacs, which used a separate MXM daughterboard for their GPU. The computer's expansion ports are mounted directly onto the logic board—the SD card slot, headphone jack, four USB 3.0 ports, two Thunderbolt ports, and a gigabit Ethernet port. As Apple has said, there is no Firewire port.

We don't see an SSD in the teardown, 2.5-inch or stick, so it seems like the model used here is the base, non-Fusion Drive model with a 2.5-inch TB hard disk drive. It's difficult to tell for certain from the one close-up whether or not the system's single fan has the same asymmetric blade layout Apple introduced with the retina MacBook Pro, but it doesn't appear to.

Interestingly, the pair of SODIMMs that make up the system's RAM are clearly removable. Anandtech has noted that the larger 27-inch iMac has a small port on the back through which the SODIMM cradles can be accessed; the 21-inch iMac seems to have the same type of RAM but lacks the port, making the RAM much more difficult to replace. However, at least the RAM isn't soldered to the motherboard.

The remainder of the components consist of a power supply daughterboard, two speaker enclosures, and a heatpipe/heat sink assembly for the CPU and GPU. There's also the camera bar at the top edge of the computer, just visible in the motherboard picture.

Our own Andrew Cunningham is busily attempting to procure a 21-inch iMac this morning for us to review, so stay tuned for our hands-on impressions.