The logic board of the iMac (21.5-inch, Mid 2011), model A1311, 2011, 21.5-inch. Known faults are being collected.
No guided tree is live for this board yet. The profile, the viewer and manual entry are there on the free plan, and the first sessions on it build the tree.
Checked on 2026-10-29 against 2 sources: corrected. Info said Mid 2010. Beetstech, Mac of All Trades and GotLaptopParts all list 820-2641-A as the Mid 2011 A1311 board (iMac12,1; MC309LL/A, MC812LL/A; APN 661-5935/5936/5937). The Mid 2010 21.5-inch board is 820-2784-A, so the CSV has these two rows swapped. Year changes from 2010 to 2011. Revision A is a placeholder until Studio records the real revisions.
Open the board in NextProbe, answer the symptom questions and follow the lit point. The free plan includes three guided sessions a month. Your own boardview and schematic stay on your machine.