iMac stuck on status bar during boot. Can't recovery from Internet or USB

I'm trying to fix an iMac (I THINK it's a 2012 or 2014) that will boot maybe one in 20 times it seems. But I'm not sure if it'll boot again to be honest. It starts, chimes after 5-10 seconds, then is stuck on the Apple logo screen with the status bar. I tried using Internet Recovery but after the spinning globe and timer count down it's stuck on the status bar again. I have a High Sierra USB flash drive that I booted from, but again the same. I can pick it from the boot menu (it sees the other partitions as well) and then it's stuck on the status bar. I have even swapped hard drives with the same results. I've done a PRAM and SMC reset as well...and you guessed it, same result; stuck on the status bar screen.

I'm beginning to think it's a logic board issue but hoping someone else can give me cause for hope as it belongs to a non-profit. Thanks!