Garrett Z-Lynk MS-3 repair

[qtrs-xcite-me]

I started detecting in 2021 and my gear included a wireless headphone set - Garrett Z-Lynk MS-3. In late 2025 the ear pads began de-laminating. I reached out to Garrett about repairs, but did not receive a response. I went on-line and found a set of replacement ear pads and installed them. Shortly after that, on 2 separate occasions, when I got to my detecting site, the headphones would not turn on despite being placed on the charger the last time used and left till the red light went off and then being disconnected (the procedure I had always followed). I decided the battery was not holding charge as well as it should. Research showed the battery listed as "not user maintainable". I ordered a replacement headset, but since I now have 2 detectors, decided I would like to see it I could repair the old set. First obstacle was I needed a .127 mm allen wrench to remove the 4 screws holding the cover of the ear piece on the gray switch side and then to remove the 2 screws holding the battery in place -spent $10 on a metric and SAE set including all sizes under .050 inches. The old battery was speced: Minamoto LP753040, 3.7 v, 840 mah. The closest replacement I could find was speced: RAEWSTCO 8003040, 3.7 v, 1000 mah. I had to purchase 2 batteries for $10. Once the batteries arrived, I had to reverse the red and black leads at the connector before installing the new battery. I completed the task and the the headset will turn on and attempt to link with the detector and will charge without smoking. I still need to actually try it out with the detector.

 

[geowizard]

Why did you have to reverse the red and black leads?

- Geowizard

 

[qtrs-xcite-me]

When looking at the picture of the circuit board above, the power socket is just above the red and orange wires. Taking the upper right corner of the pic as "up" compared to the power socket, when the original battery was plugged in the red wire was on the left and the black wire on the right. Had I plugged in the new battery, as it came, the leads would have been backwards. Most of the ads I reviewed for these batteries included warnings to make sure of the polarity before plugging in the new battery. I don't know if the standard for polarity changed or if product producers stipulated a non-standard orientation.

 

[Carl-NC]

There's no standard, it's a 50/50 chance. Good that you checked it.