7 Wire Microphone Earbud to 3.5mm TRS Jack Replacement

I have an old Samsung earbud which uses this old jack which is obsolete. Hence I tested it out by changing it into a TRS 3.5mm Jack. It has 7 wires which is uncommon hence the decision to make an Instructable to share.

This is my first time doing one so please be kind, share and educate me~

Step 1: Step 1 : Open the Microphone Box to Identify the Wires

Dispose of the old jack and open up the microphone box to identify the wiring. The left side shows connections to the earbud while the right side is the connections to the jack. Note the microphone and the button on the back side of the PCB so we don't close the box in a wrong orientation.

Look at the right side to identify the color code. In this instructable we're only looking at the earbud's functionality and not at the microphone as I couldn't get my hands on a TRRS jack yet. Perhaps I'll update this instructable later on. L+ is for the left channel, R+ is for the right channel and GND is for ground.

SC acts as a boost for the signal but I don't want one side to be louder than the other side so put it away. M+ and M- are signals for microphones while ADC is the analogue to digital converter for the microphone which we'll not be using (correct me if i'm wrong).

So now that we know L+, Left Channel is the purple wire, R+, Right Channel is the black wire and GND, Ground are the loose wires around.

Step 2: Step 2 : Solder the 3.5mm TRS Jack

Get the TRS jack ready and open the cover. TRS stands for Tip-Ring-Sleeve for the jack part. The connections are usually Tip for Left, Ring for Right and Sleeve for Ground. Their connecting pins in the cover are labelled in the picture.

Longest pin = Sleeve pin = Ground pin
Short pin center connected = Tip pin = Left pin
Short pin between plastic = Ring pin = Right pin

REMEMBER TO PUT ON THE COVER BEFORE STARTING ANYTHING ELSE! Wouldn't want our jack to be naked.

Solder the purple wire to the left pin, the black wire to the right pin and the loose wires to the ground pin. Arrange the remaining wires properly. I just cello-taped them to the wire. Avoid them obstructing the connection and also made sure they are within the confinements of the cover.

Step 3: Step 3 : Continuity Check

You can perform some continuity check between the Tip and the Left Channel, the Ring and the Right Channel, the Sleeve and the Ground. Just connect a multimeter between those 2 points and check for their resistivity, if it's near to 0 it is a good connection.