Apple iMac A1418 21" Late 2015 MK452LL i5-5675R 3.1GHz 8GB Logic Board 661-03282
Apple Genuine 661-03169 Logic Board 3.2GHz Quad Core i5 for iMac 27 inch Retina 5K Late 2015
Apple Computer iMac 27-inch 3.5 GHz Core i5 (i5-4690) iMac 27-inch 4.0 GHz Core i7 (i7-4790K) Compatible Order Number MF886LL/A Compatible Model Number
iMac 21.5" A1418 Late 2015 Logic Board 2.8 GHz Core i5 16GB Ram || NO - Part Haven
Apple iMac 27" A1419 2015 5K Logic Board Motherboard Faulty Sold As Seen | eBay
Logic Board 3.3 GHz i7 16GB Ram iMac Retina 4K 21.5" Late 2015 A1418 W - Part Haven
A1418 Late 2015 I5 3.1ghz 8gb 4k 820-00431-a Mk452 Logic Board Motherboard Mainboard For Imac 21.5" - Motherboards - AliExpress
Original A1419 Motherboard 820-00291-A 820-00134-A 820-00292-A For iMac 5K 27" Logic Board 2GB Graphic Card 661-03171 Late2015 - AliExpress
Probably of no use to anyone here, but the 2.8GHz late 2015 iMac logic board requires a different heatsink than the 1.6GHz board because the CPU is in a different location. Ask