A look inside the new flat-panel iMac

A reader alerted us to a pre-release draft of service instructions for the new flat-panel iMac, which was posted on the Internet. (Update: the link appears to have been removed since our initial posting.) The document clearly states that the information is subject to change, however, in its current form it presents a detailed look inside the new iMac, including instructions on how to install RAM upgrades and replace the hard drive. The document is some 106 pages in length and is split between the "Flat Panel iMac - Take Apart" section (1-90 pages) and a "Flat Panel iMac - Upgrades" section (91-106 pages). Here are a few interesting items that caught our attention:

• The document shows a "service stand" which cradles the iMac so that the bottom is accessible It appears to us that the service stand is several pieces of packing material cut to support the iMac when its on its side.
• The bottom plate is held in place with Phillips screws, and removing it provides access to the AirPort card and one RAM slot. Removing the sub-plate to expose the unit further requires a Torx 15 screwdriver.
• Thermal pads are used to connect three surfaces inside the housing. The document notes that whenever the logic board is exposed, these pads must be replaced.
• The AirPort antenna is located inside the screen housing, and appears to be about 4 inches longer than the screen is wide.
• It notes that there are two memory slots. One slot is user-accessible, and uses PC-100 144-pin SO-DIMMs up to 256 MB, while the other slot requires the logic board to be removed ("it can only be installed or replaced by an Apple Authorized Service Provider"), and uses a PC-133 168-pin DIMM up to 512 MB.

Update: The RAM spec that appears in the service document is incorrect. BOTH slots require PC-133 RAM. Thanks, Andrew McNaughton! (We also suspect that the 256MB limit is wrong considering the iMac's tech specs page states 1GB RAM is supported). In either case this reminder applies: given it is a draft, the entire document should be considered FYI only.

Update: Others have reconfirmed that PC-100 can be used in the user-accessible slot. Let's wait and see.

In general, it appears to us that accessing the logic board is not significantly more difficult than present iMacs, although it continues to be a non-trivial task and presents several new challenges, including supporting the screen while dissembling the base and the use of thermal pads and thermal paste during reassembly.