Right channel audio gone

The right channel audio does not work (bottom loudspeaker, right channel with wired earbuds. bluetooth is fine). I've had this issue for a while, and I decided I would replace the parts that (I thought) were defective. I replaced the bottom loudspeaker, the 3.5mm jack, and the antenna/sound board (I had also done other repairs during this such as replacing the bluetooth antenna, the battery, and the charging flex cable, all of those seem to be working fine now. It should also be noted that my flex cable replacement and the antenna/sound board replacement were ordered separately and did not arrive as one piece.) Even after doing all of that, there is still no audio coming from the right channel. I honestly don't know what to do now.