Up for sale is a used and non-working logic board for a 27" iMac A1419.  This one came from a 2017 5K retina model with Radeon Pro 5580 GPU and 8GB of VRAM. 

Power issue and works sporadically.  Fully tested all components and diagnosis narrowed down issue to this main board.  Generally boots up works perfectly for awhile and then powers itself down.  Seem to be a common issue with these boards so if you're handy, it may be an easy fix.

Board only.  No CPU or RAM is included.

Shipping will be free anywhere in the US.  Thanks for looking!