mid-2011 imac no power--logic board? | MacRumors Forums
27inch iMac (late 2013) Diagnostic LED 1 flickers then off, already tried a new psu(AliExpress). Any ideas? do I try logic board next? : r/LukeMianiYouTube
iMac motherboard repair - No display No backlight - YouTube
mid 2011 27" won't power up and only 1 diagnostic LED | MacRumors Forums
How do I see the Diagnostic LED lights? - iMac Intel 21.5" EMC 2308 - iFixit