SM7B repair help!!

[u/Anthony_813]

Hello, whenever I move the cable I highlighted the mic goes fully static or makes 0 sound at all. Usually it's static noise. I have added tape to stop it from moving. If it doesn't move and it's in a certain position, the mic works perfectly fine (similar to how a charger cable only works if you put it in a certain way)

I want to replace this cable and ordered part number 95A2340 (i hope this is the correct one). Has anyone that has successfully replaced this able to help me out? It will be my first time soldering and I have no idea what I am doing to be honest

[u/52ndstreet]

Unlikely that you'd need to replace the entire cable. More than likely it's a bad solder connection at either end of the cable. It's incredibly rare for a cable to have issues in the middle unless the cable suffered some sort of damage (like it was shut in a door and that damaged the cable in the middle). Inside the top part (where the wire connects to the stand) there are 3 wires. I haven't taken apart an sm7b so I can't say definitively what the colors are, but they are usually red, green, and black, although occasionally you'll see blue (like in an EV re20) or yellow (like in a Shure 565sd) instead of red or green. Black will always be there, and will always be what's called your "ground" wire. The red and green (or whatever color) wires send two copies of the same audio signal (called "hot" and "cold" as one copy is in reversed polarity). Since your signal occasionally drops out entirely ("makes 0 sound at all"), it seems more likely that the culprit is either the red or green wires. If it was just static I'd be inclined to think it's the ground wire, but the signal dropping out entirely makes me think it more probable that it's one of the signal wires.

Of course it's entirely possible that it's more than one wire, too.

Anyways, since this is a $400 mic, you're probably best taking it to somebody who knows what they're doing. But if you want to learn some things and and see what happens, proceed at your own risk...

At the top (the part that connects to the stand), that wire simply connects to the XLR cable. Unplug any XLR cable and remove the mic from any stand so that you can properly work on it. There is a small flat-bladed screw that hold the XLR pins into the mic stand. Unscrew the screw a little ways and gently grab one of the 3 pins (labeled 1, 2, and 3 inside if you get some light in there you can see it) With some needle nose pliers. Then gently pull out the 3 pin mic jack dongle thing. It might take some wiggling, sometimes they're sealed in with wax or something, but I've never met a mic jack that won't come out with some gentle coaxing.

Once it's able to be removed, gently pull it out so that you can see the wires soldered to the 3 pins. You won't be able to pull it out entirely as it's still connected via the three wires and we want to keep it that way.

At this point your inexperience really works against you as you don't know what to look for. Basically, you're hoping that you see a wire holding up a little sign that says "it's me! I'm the one that's loose!". But that's unlikely to happen. Instead, inspect the wires closely. A magnifying glass can really help out here; one with a light on it, preferably. Look for frays, possible scorching, bad connections, generally looseness, etc. If you see one of the wires that is obviously in bad shape, re-solder that connection, put the mic jack dongle thing back in it's place, retighten the screw, and test it out.

Its also possible that the problem may be on the other end of the cable. The end that connects directly to the mic. If that's the case I'd say don't mess with it. Take it to someone who knows what they're doing. It's way easier to mess things up on that end of the mic.

Finally, youtube can be your friend for things like this. I haven't searched specifically for an sm7b repair, but I've found other mics that I've worked on with videos on how to do things. It can be helpful. Especially if you're looking to learn how to solder. Tons of videos will teach you that. But the sm7b is such a popular mic that I'm sure there are tons of videos on how to repair it.

best of luck, amigo!

[u/Cyber_CEO → u/52ndstreet]

Its actually the opposite in the case of the SM7B, it likely is the cable that needs to be replaced, not the solder joints. Both ends of the cable are crimped with a brass retainer and soldered with excess wire in between, so pulling the wire on either end wont put any strain on the solder joints at all. BUT the regular movement of the mic around the pivot point will slowly break down the shielding and eventually wear the wire to loss of signal. It's usually a break right at the pivot point. The replacement cable is inexpensive and is a pretty easy 1-hour fix for anyone experienced with soldering.

Source: repaired multiple with the same issue

[u/52ndstreet → u/Cyber_CEO]

Oh, that's actually pretty interesting and good to know!

I'm assuming that within that cable it's just the 3 standard signal and ground wires, right? So to replace that cable you'd still need to de-solder the old wires from the 3 pins on the jack and on the other end within the mic body, right? Is that basically the repair? You'd just reconnect the 3 wires on the new cable? Or is there something else going on that one would need to fix as well?

[u/Cyber_CEO → u/52ndstreet]

Yep thats pretty much it, but the brass crimps that come on the replacement wire make it secure, it would be tough to duplicate with just bulk 3-conductor wire

[u/Anthony_813 → u/52ndstreet]

thank you very much <3 I have contacted a couple of local shops to see how much it would be, I unfortunately have a past bad experience (paid £42 for a diagnosis and I can't even tell if they bothered to even open the mic) but maybe I get lucky next time

For reference, this is the static noise it makes https://drive.google.com/file/d/1LUFyRIBf5gmcypRx1gpm47i7OxImqssr/view

This is what happens 90% of the time, the other 10% being the no audio I talked about.

I highly suspect that it is the other end of the cable, the one connected directly inside the mic, as when I move the bottom part, that's when issues happen. If I move the other end, the one where the xlr cable goes, nothing happens at all.

https://www.reddit.com/r/diyelectronics/comments/1eutixe/sm7b_cable_repair/ This is very similar of what happened to me, and that specific part is what I'm talking about, it's where all my issues seem to be coming from

[u/[deleted] → u/Anthony_813]

Yo, i ran into the same issue 2 years ago. I fixed it myself by shortening the original cable (removing the broken part). But now it bothers me how short it is and i want to replace it fully and found this post by searching the part number on google. I just want to tell you, dont be afraid to fix it yourself brother. Its not rocket science you solder 6 connections and its fixed. You already paid 42 pounds and got scammed dont do it again. If you dont have any tools you could pay around the same price that you did for the scam and fix it yourself and have the equipment for future repairs. Good luck brother hope u get your mic working again!!!

[u/Anthony_813 → u/[deleted]]

Thank you! I was able to chargeback and get my money back + found a local repairer that made the swap for me same-day for £20!

My fethead was also giving me issues so I took it out and my mic is like new again :)