Garmin Fenix 3 is still one of the most favored multifunctional GPS smartwatch brands produced by Garmin due to its durability and high performance. However, after several years of usage, parts like the battery, screen, charging ports, and even the housing can get worn out.
Nevertheless, there are a lot of problems that do not require changing the whole device but need repair only. If you plan to replace the battery of your Garmin Fenix 3, change the LCD screen of your Garmin Fenix 3, or install a new back case of your Garmin Fenix 3, then the first step that you have to do is learn how to take apart Garmin Fenix 3.
The following instruction will show you how to do it as well as will introduce you to the main parts inside this device.
Garmin Fenix 3 Troubleshooting
There are several situations where opening your Garmin Fenix 3 becomes necessary.
Common repair scenarios include:
- Battery no longer holds a charge
- Watch won't power on
- Cracked or damaged LCD display
- Touch or display issues
- Damaged rear housing
- Water damage inspection
- Internal cleaning after years of use
Instead of replacing the entire smartwatch, replacing individual Garmin Fenix 3 repair parts is often faster, less expensive, and extends the service life of your device.
Before disassembling the Garmin Fenix 3 watch
Tools needed: To repair a Garmin Fenix 3, you will only need a T6 Torx screwdriver, a T5 Torx screwdriver, and a pry bar. An anti-static work mat is also required.
Note：
- Please completely power off the watch.
- Unplug all charging cables.
- Clean the exterior of the watch body to prevent dust from entering the device.
- Please perform this operation on an anti-static work surface.
How to Disassemble Garmin Fenix 3 Step By Step
Step 1 – Remove the Front Housing for Garmin Fenix 3
To begin how to disassemble Garmin Fenix 3, place the watch face upward.
Using a T6 Torx screwdriver, remove the five screws securing the front housing.
Keep the screws organized, as they are very small and easy to lose.
After removing the screws, carefully lift the display assembly.
Do not pull the display away quickly.
The Garmin Fenix 3 screen remains attached to the motherboard through a ribbon cable.
Step 2 – Disconnect the LCD Display for Garmin Fenix 3
Slowly separate the Garmin fenix 3 display assembly from the watch body.
Locate the display ribbon cable connected to the motherboard.
Using a plastic spudger, carefully lift the press-fit connector.
Once disconnected, remove the display assembly completely.
If your repair involves how to replace LCD screen for Garmin Fenix 3, this is the step where the old display is removed.
Avoid bending the ribbon cable or scratching the connector during removal.
Step 3 – Remove the GPS Antenna
With the display removed, you'll have access to the internal components.
Locate the GPS antenna positioned on top of the motherboard.
Carefully lift the antenna from its mounting position.
Place it in a safe location until reassembly.
Although this component rarely fails, it must be removed before accessing the motherboard.
Step 4 – Remove the Garmin Fenix 3 Motherboard
Using a T5 Torx screwdriver, remove the two silver screws securing the Garmin Fenix 3 motherboard.
Precision tweezers are recommended for lifting the screws after loosening them.
Carefully turn the watch over.
The motherboard should slide out naturally.
When reinstalling the motherboard later, remember that it slides underneath the retaining lip rather than being pressed straight down.
This helps prevent damage to the board.
Step 5 – Remove the Replacement Battery for Garmin Fenix 3
With the motherboard removed, the battery becomes fully accessible.
The battery is lightly attached to the motherboard using adhesive.
Using a plastic spudger:
- Separate the battery from the motherboard
- Lift the battery connector upward
- Disconnect the battery carefully
Never use excessive force.
Avoid puncturing or bending the lithium battery during removal.
If your watch has poor battery life or shuts down unexpectedly, installing a replacement battery for Garmin Fenix 3 is the recommended repair.
How to Reassemble Garmin Fenix 3
Reassembly is completed by reversing the disassembly steps.
Install the New Battery
Position the replacement battery for Garmin Fenix 3 onto the motherboard.
Reconnect the battery connector carefully.
Ensure the connector is fully seated.
An improperly connected battery may show 100% while charging but prevent the watch from powering on.
Reinstall the Motherboard
Slide the motherboard back underneath the retaining lip inside the watch housing.
Secure it with the original T5 screws.
Reconnect any components removed during disassembly.
Install the GPS Antenna
Place the antenna back into its original location.
Ensure it sits flat and is not pinched by surrounding components.
Reconnect the LCD Display for Garmin Fenix 3
Reconnect the ribbon cable securely. Before closing the watch completely, power it on briefly to verify:
- LCD displays correctly
- Backlight functions
- Buttons respond normally
- Battery charges properly
Testing before sealing the watch can save considerable time if adjustments are required.
Reinstall the Front Housing for Garmin Fenix 3
Align the display assembly with the watch body.
Replace the five T6 Torx screws.
Tighten them gradually using a cross pattern to ensure even pressure on the waterproof seal.
Avoid overtightening the screws.
Tips for Successful Garmin Fenix 3 Repair
To improve your repair results:
- Always disconnect the battery before working on other components.
- Use plastic tools whenever possible.
- Organize screws by step.
- Photograph cable locations during disassembly.
- Replace damaged waterproof seals.
- Test the watch before final assembly.
- Use genuine-quality Garmin replacement parts whenever possible.
Common Garmin Fenix 3 Replacement Parts
Many Garmin Fenix 3 repairs require only a single replacement component.
Popular parts include:
- LCD display for Garmin Fenix 3
- Replacement battery for Garmin Fenix 3
- Back cover case for Garmin Fenix 3
- Charging contacts
- GPS antenna
- Button assemblies
- Waterproof gasket
- Mainboard
Replacing only the damaged part is significantly more economical than purchasing a new smartwatch.
Final Thoughts
Learning how to disassemble and reassemble Garmin Fenix 3 allows you to repair many common hardware issues while extending the life of your smartwatch. Whether you're replacing the LCD display for Garmin Fenix 3, installing a replacement battery for Garmin Fenix 3, or fitting a new back cover case for Garmin Fenix 3, careful disassembly and proper reassembly are the keys to a successful repair.
Using high-quality Garmin replacement parts and following a systematic repair process helps restore your Garmin Fenix 3 to reliable working condition, saving money while keeping your trusted outdoor companion ready for many more adventures.
