Wont charge even after replacement parts

Hi,

this is for the s20 series along with the note 10 series (same issue ).

I have had multiple s20s and note 10s come in for not charging. wether they dont charge at all, or will still charge but show the yellow triangle, or just dont show any current at all.

I have replaced the charge port board, 2 flex cables along with the wireless charging /nfc part along with the battery and nfc pcb connectors. I have tried multiple parts from multiple suppliers multiple times with the same results, still wont charge. About 10% of these 2 models that come in one of those 4 parts fixes the issue and all is well. the other 90% are failed. I know there is the ic chip under the metal cover up and to the right of the battery connector however haven’t dug into that yet.

anybody else run into this?

thanks in advance!