Both Triggers not registering at all.

L2 and R2 buttons not registering at all. new triggers new pads and no visible damage or excessive wear to the large ribbon cable. I’ve connected it to pc and used html5 to test and get zero response. I have reset factory settings on the system as well as a hard reset controller and have had no success at all. what could be causing this. I have the ability to solder and do hot air rework so I’m open to any and all solutions.