Shure sm58 wireless handheld mic problem

[dpak]

One of my sm58 wireless mics (ulx2-m1, if that helps) is sending out a signal (the receiver ls getting it) but no audio. I've isolated the problem to the two chip boards (if that's the right term) in the body (where the display is attached). I can swap out every other part and they work on the other mics.

There is nothing obviously wrong with the boards/chips - no corrosion, nothing that looks loose. And it's 662-698 MHz (yeah, I know). Is this a case where I just need to save the parts for the other mics and give up trying to fix it?

Thanks in advance!

 

[JD]

Because of the frequency range, I would scrap it for parts. Often, issues where everything looks ok but a mic doesn't work can actually be related to a software issue. Unfortunately, there is no simple route to reload the software outside of shipping it in. Again, I am not sure they would even service it due to the 600MHz range.

 

[josh88]

Aside from what JD mentioned, when you say the receiver is getting signal, you mean that when you speak into the mic you're seeing levels/the signal lights react at the receiver, or are you just seeing battery level showing that it has found the handheld? If you're seeing the signal lights moving, to me that would indicate the issue is between the receiver and your board.

You've tried using that handheld with a different receiver and a different handheld with that "problem" receiver? If you change frequencies on the handheld to match a different receiver and it works, that narrows it down pretty quickly.

 

[TimMc]

You are likely being hit by T Mobile's new service or TV stations that moved overnight. Scrap it all. Even if it ain't broke...

 

[dpak]

You've tried using that handheld with a different receiver and a different handheld with that "problem" receiver? If you change frequencies on the handheld to match a different receiver and it works, that narrows it down pretty quickly.

And I thought I was so smart. I thought I had done all you said but after double checking, it turns out the mic is fine - it seems to be the receiver that is the problem. The mic works if I put it on another receiver. The receiver in question gets the signal - the RF light and the battery icon will light up when the mic (and I've tried different mics with it) but it still won't register any sound when using a handheld mic. Just to complicate the situation, it will register sound from a body pack (and the channel on the receiver doesn't seem to matter).

It's been a long day. I'l fiddle around with it tomorrow (and RTFM for the receiver) and post any results.

 

[Jay Ashworth]

So, to be clear, you're saying that if you put that receiver and any mic on the same freq by themselves, you get RF antenna markers, and a Battery level indicator, but no audio?

Does the freq matter?

 

[FMEng]

It could be that the receiver squelch is set too high. Body packs might produce a bit more RF than the handheld, opening the squelch. Try lowering the squelch setting.

 

[dpak]

Well now I just don't know a damn thing. The frequency on the receiver didn't seem to matter, nor did the mic used (and I checked the gain on the mics). RF would light up, but no audio. I just spent some time checking the wires in back, including making certain the receivers were hooked up to the antenna boxes correctly (we had all of the receivers pulled out recently for an event, and I had students put them back after showing them how to connect things). I did switch a few wires around, but I don't think I did anything to the receiver in question. It is now working, and I've tried different mics and different channels to make certain. Maybe (?) it was because it was not hooked up to the antenna box, but it was getting a signal and I'm right in the control booth.

Thanks for the replies and the suggestions!

 

[Ben Stiegler]

Antenna box ... best practice if you are using active splitter is to also power the receiver from it. See any power out jacks on back? Shure,AT, etc are universal DC in so you can mix and match - RTFM or use voltmeter if u r ever uncertain re mixing brands.

Check out RFVenue - they have a very affordable spectrum analyzer (under $300 if I recall) which you leavepetmanently live in your venue. Thrn you’ll know right away if tv news or public safety rolls up outside and interference mysteriously begins mid show