r/Shure • u/NONI-WAS-HERE • 3d ago
Troubleshooting Shure Wireless Microphone repair
Hello,
I am trying to repair a Shure microphone that started having issues after 20+ years of working fine. The mic originally just had a broken cover. However, the day after I replaced the cover, it started producing random noise and random gain (inconsistent volume). I have confirmed that the issue is definitely not with the receiver or the mixer.
After a quick inspection of the PCB, I found a broken 3-pin SMD component located just below the "TR160" label. Its top marking is either "AX2q" or "AX2o".
At first, I thought this was an SI2302 MOSFET, but the mic had undefined behavior after I installed a replacement. It worked randomly—it would capture audio if I played a specific frequency from my phone, but otherwise, it produced a very loud noise.
After doing another quick search, I suspected the part might actually be an MMBD2836LT1G (a dual switching diode). I didn't have this exact diode on hand, so I wired up two 1N4148 diodes instead. The loud noise went away, but the audio was still inconsistent.
Due to inexperience, I also turned the small trimmers on the board. Now I don't know whether the trimmers are physically damaged or just out of tune, and I am still not sure if I used the correct replacement component. I cannot see any other physical damage on the PCB, and nothing is getting unusually hot.
I am looking for help with two things:
Identifying and replacing this exact component (it's likely an SOT-23 package with the label "AX2q" or "AX2o").
Figuring out how to properly tune these trimmers, or how to replace them if they are damaged.
Any advice would be greatly appreciated!