I am making this post to clarify the fix that /u/Chiny_1990 submitted 2 days ago. Imgur link with guide pictures.

I found that only insulating the the tops of the screws from the daughter board wasn’t enough to 100% stop the EMI that I was expierencing. I also removed the daughter board and insulated the board from the chassis with small pieces of electrical tape as well.

I have been using my deck for 2 days now with absolutely no issues. My audio is now crystal clear coming through my very sensitive IEM’s with zero EMI. I examined the board and found that there is no “power” or control or signal voltage that runs through this board that could cause any catastrophic affect from insulating it from the chassis of the steamdeck. This board doesn’t have anything to do with Bluetooth or WIFI, it only supplies audio signals to the 3.5mm jack and has two volume control buttons to adjust the steamdecks volume.

I hope this helps anyone who can/will attempt this fix themselves and alleviates any concerns people have about this possibly damaging their decks if they attempt this repair.

Obviously I take no responsibility if you damage your deck while performing this fix, and I understand that Valve should fix this issue themselves, but I have had an open ticket with them for 4 days now and tried all of their fixes that they have suggested and none of them have worked because this is a hardware issue and not a software issue. There wasn’t a single problem with my system besides this EMI problem, so to me it is worth performing this fix myself instead of waiting around for Valve to come up with something or getting another unit to only have the exact same problem mine had.