Does someone know the pinout for the power connector for the Apple 820-1096-A board?
If you're searching you'll have better luck looking for a slot-load iMac pinout. I doubt most/any websites have a list of pinouts by board part numbers.
You should find what you need in this thread discussing iMac to ATX conversions.
Some of the links posted later in the thread have the power connecter pinouts.