Wire-Lists#4: SM Transmitter Cleaning – Tips for Battery Doors and 5-Pin Jacks

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SM transmitters might go through hell on the job --  but they don’t have to look like it.  Battery doors and the 5-pin jacks are particularly susceptible to wear and tear. These tips can help:

Battery Doors

IMG 3410If the battery door and mating surface on your SM series transmitter look like this and are starting to become difficult to open, don’t scrub them with an abrasive!  We’ve seen a few units that were damaged by steel wool, sandpaper and other materials. Multiple problems can be created as a result, such as getting particulate (tiny pieces that break off) into the unit, damaging the battery contacts on the door, and removing the conductive coating from this area and even the entire housing. 

IMG 3411To clean, we recommend Wright’s Silver Cream (available in Walmart and Home Depot; under $10 for a small container that will last you a year or more) to clean the door and housing. 


Using a small amount of cream, allow to dry and then GENTLY clean the cream from the door and housing. If excessive force is used when removing the dried cream, the conductive finish can be removed along with it.

Removing the thumbscrew from the door can make cleaning easier, though it should be done in a specific manner. Instructions on how to properly do that can be found HERE. Please keep an eye on the e-clip and washer which, if either are lost, damaged or replaced incorrectly,  can cause the thumbscrew to not seat properly in the case and cause wear to both the door and mating surface.

Your end result after cleaning with the cream will look like this:

IMG 3412

The 5 Pin Microphone Jack Opening

The 5 pin opening and contacts for microphones on SMs can likewise collect grease and dirt. You might think that an easy fix for this would be to use a contact cleaner such as WD-40, Goo Gone or acetone, but there are two potential problems with this idea:

  1. Any type of liquid can seep into the unit under surface mount parts and thru-holes and build up on the circuit boards. We don’t want to tell you how many units we have gotten in due to this type of “cleaning”…or how many of those transmitters ended up being a lost cause.
  2. The labeling on many contact cleaners will read something like “compatible with most plastics, paints and rubber surfaces.” The problem is that the labeling is not specific enough. Which plastics, paints or rubber surfaces? Theoretically, you could clean the battery contact and the 5-pin, but there is nothing keeping the liquid out of the unit.

So how do you clean the 5-pin jack?

First, you can try canned air. You probably have some lying around (if not, it’s inexpensive) and it will blow out any dust or lint-like particles inside. If that doesn’t work, you can do what we do here.  We clean it using alcohol and an acid brush (used to apply paste flux for soldering; cost under a dollar and available in any hardware or home improvement store, often in multi-packs), while holding the unit upside down to keep the contaminants out of the transmitter.

Alcohol and brush  Cleaning with the brush 

All of these suggestions will can go a long way in ensuring that they not only work well and stay out of Repair, but look like new, longer.