Yesterday I replaced a broken 3.5mm jack on my 2.1 speakers and thought it was working well however when I plugged my headphones into the speakers I could hear a very loud static noise. I can hear audio coming out of them and I can barely hear the static noise when the audio is coming out the speakers and not headphones.
I noticed that even if the jack was not connected to anything, as soon as the speakers are connected to a mains plug, the static noise can be heard.
Any ideas on how to fix this? I'm not great at soldering so I feel like this may be the issue. Many thanks
You may have applied excessive heat to the circuit board when you soldered the jack. That could lift a circuit trace from the board or damage a component that is soldered to that trace upstream of the jack.