Technical information

Troubleshooting Introduction - 1
Introduction
Troubleshooting procedures for the iMac (Early 2001) computer
are almost identical to the iMac (Summer 2000) computer. Read
below to see what’s new and different.
Troubleshooting information for the iMac can be found in Apple’s
Knowledge Base (http://kbase.info.apple.com) or in the Tech Info
Library (TIL). Refer to the next two pages for search tips.
What’s New and Different:
1. Important: Unlike previous iMac models, some versions of the
iMac (Early 2001) logic boards include a thermal pad
(922-4364) to help cool the microprocessor. If this pad is
not replaced when the main logic board is separated from the
divider panel assembly, the microprocessor may overheat
and become damaged.
It is crucial that a fresh thermal pad be used each time you
detach the logic board from the divider panel. (An exception
would be if you are simply testing the logic board and only
detach it for a few minutes).
2. There are new part numbers for the power/analog/video
boards; 661-2465 (HH, with a switch at SW901) and 661-
2466 (LG).
3. North American models have white power-on LEDs.
4. On the 661-2427, 400 MHz logic board, connector J7 is
where you test for power on the logic board (same location as
iMac (Summer 2000) computers).
5. The 400 MHZ Ver.2, 500 MHz, and 600 MHz models use a
different divider panel that the 661-2427 400 MHz logic
board. Refer to Take Apart/Logic Board/Thermal Pad Instal-
lation for a picture of the new divider panel.