Garmin Fenix 6X Pro Disassembly or Teardown whatever you say…


It’s been a long time since I torn something down. So lets destroy something, but what? 🤔 Oow, released 6 series of its Fenix line. And I have a Garmin Fenix 6X Pro on my . So? I can start opening it and it’s definitely a nice thing to post on the blog. 😀 Where’s my T6 or…?

Garmin released Fenix 6 series this summer with many updates to older Fenix 5 and 5 plus series. They are more energy saving during activities, faster, better, and more expensive with bigger displays, have more animations and a long waited non-MTK chipset. 😀

The watch internals is sandwitched between the front bezel and back metal plate which is holding the HR and oxygen saturation sensors. Both bezel and the back plate is holded by five screws. I’ll start from the bezel and I’m not planning to touch the back. All I wonder is accessible just by removing the bezel…

Without the screws… 🙂

After removing the screws and bezel (Of course, after disassembling the display ribbon from the motherboard!) the motherboard of Fenix 6X Pro is in front of us, with a large EMF shield on it. You see the display connector and another connector that’s moving the power between the motherboard the battery, vibrating the vibrator and measuring your HR.

Here, I miss (Or actually I don’t) a module I saw in Fenix 5X and Fenix 3. That was the GPS antenna that stayed on the top of the case. Now, this device has long pins that touhes the metal pads on the bezel. We’ll look at them later, but it seems Garmin’s used newer antenna design after Fenix 5 Plus series. In the end a real EXO antenna?

Before removing the EMF shield, there is a chip outside it.

It has the NXP title on it and what that title usually reminds me is Near Field Communication or NFC and wires going to the display connector port, may be the proof. NXP PN81T, 81T17 probably manages the NFC and wireless payment functionalities of the device. Yeah, usually those NFC antennas are placed below the display.

I remember that, there is a buzzer for some sounds below the shield. But that’s maybe my least used function, so lets switch to motherboard. Yeah, I even didn’t photograph that buzzer. 😀

There we see a big electrical isolation shield to prevent any shortcuts, and a few ICs around. Actually one of them is what Garmin downgraded going from Fenix 5X to Fenix 6X Pro.

Below image you’ll see that Fenix 5X menu displays an item with a number higher than Fenix 6X Pro. No, battery voltage and percentage is not what I want to show. It is the RAM amount! Fenix 5X has 32 MB of RAM to store the map data for quick random access. However, Garmin Fenix 6X Pro only has 17 MB of it. Actually it has 16 MB external RAM and probably counts 1 MB on the main CPU, too.

Less RAM may seem bad, but in reality it doesn’t translate to bad performance. When crawling in maps I feel it’d perform better with more memory, but for normal usage it doesn’t seem bad or missing it. Actually, Fenix 6X Pro is faster then Fenix 5X when routing.

Garmin Fenix 6x Pro has WINBOND W987D6HBGX6E 128Mb (Or 16 MB by better means.) Mobile LPSDR RAM running at 166 MHz speed and 1.8 volts. Except storing some maps data for navigation, it can be used by IQ apps too. Garmin watches with mapping capabilites, have almost 1 MB more RAM dedicated to Connect IQ apps due to their external RAM modules.

Near the RAM, we see a large chip under the metal frame. That’s the Toshiba THGBMHG8C2LBAIL or sth. like that ‘cos I can’t read the label under the frame.

Toshiba THGBMHG8C2LBAIL 32 GB eMMC memory.

It’s a 32 GB 15nm eMMC chip where your device store your maps and sporty music library with songs, pumping youth blood to adult veins. 32 GB is not enough for phones nowadays, but much more than enough for a sports watch with smart features. Unless you want to put the world map of on it, of course… Or a HDD sized music library etc…

Another IC we see is labelled MAX20303B.

Maxim Integrated MAX20303B…

MAX20303B is a power management IC by Maxim Integrated. It’s kinda like the electrical substation of the watch. It charges the battery, gauges or estimates its capacity, regulates voltages etc. A Maxim Integrated PMIC solution for wearables with lithium ion batteries. A long read datashit.

Near the power management IC, there is an empty chip space. Positioned near the PMIC, it motivates me to think it may be sth. related to the solar charge features of Fenix 6X Pro Solar series.

1M AMAPH – Ambic Micro Apollo 2.

Another tiny IC inside the frame but outside the black sticker is the Ambic Micro Apollo 2 MCU. It’s a 48 MHz ARM Cortex M4 MCU with 1 MB flash and 256 KB RAM. I don’t know its function on this device. However,datasheet says it’s good for sensor hub or some radio functionality.

Now, let’s remove the black sticker and continue to see the parts of the brain inside.

Go, go, go…

Ooo, yeah! We have more chips there… Let’s dig in…

NXP Kinetis MK28FN2M0ACAU15, seems to be the main control center of the device. Garmin used this processor in the Fenix 5 plus series too. Older Fenix 5X had Kinetis K61 version. Kinetis K28F is 150MHz ARM Cortex M4 CPU with single precision FPU. It has 2 MB flash memory and 1 MB SRAM. It has 8 KB I/D and 8 KB system caches. MCU has dual USB controllers. Around 6 MB/s USB transfer speed I get is better than 1 – 2 MB/s of Fenix 5X. Additionally, it has 32 bit SDRAM controller, which makes it possible to put an SDRAM module on the watch and use to load map data. Top frequency of 150 MHz is in HSRUN (high speed run) mode and that’s a mode preferred to stay for a very short periods on small battery powered devices. Think it like overclocking or Intel’s Turbo feature on Core processors. Normal RUN mode seems to reach 120 MHz but it’s managed by the Garmin’s firmware and drivers etc. As one of the main feature of these devices is low battery consumption, all the CPU’s on the watch may be running at a much lower frequency than their supported top frequencies.

ATWILC 1000B UU  is placed near the CPU and it’s an Atmel 802.11 b/g/n WiFi Module with 72 Mbps max rate. It’s a module Garmin has used since Fenix 5 series or even earlier models.

M9240N U12835 labelled chip. I don’t know what does it exactly do… But due to the size and placement, I’m sure it does something important. It is probably a 128 Mbit SPI flash memory chip from Macronix.

X8 0X4R. Another chip with unknown function…

Cypress CYW20719, BT 5.0 baseband processor with 2.4 GHz transceiver with BLE, EDR and BR. This seems to be the chip responsible for the Bluetooth music transfer to the wireless headphones and BLE connections. It has its own 96 MHz ARM Cortex M4 processor and has 1 MB flash, 512 KB SRAM and 2 MB ROM. It seems to be a capable chip, so it may even have more functions like playing the music tracks etc. Only Garmin knows the real functions…

D5603 904 B20J. Long awaited, Sony CXD5603GF GNSS Chip. Garmin’s salvation from old MTK 3333AV found in almost all previous watches including Fenix 3 and Fenix 5 series… Garmin watches were criticized for having bad GPS performance on their forums and MTK 3333AV was seen the main culprit. Check the Garmin forums again, and you’ll see some posts comparing the current watches with some devices and say Garmin GPS is still bad. Sometimes people never like something. 😀 For me it’s neither bad or nor much better than the old looking at the tracks. This has many other factors like antenna design etc… The new chip by Sony supports GPS, GLONASS, Galileo, BeiDou and QZSS constellations but not all are supported by Garmin. It’s possible to use GPS only, GPS + Glonass and GPS + Galileo modes. It’s really a low power chip with 6 mW during continuous tracking. My Fenix 5X experience was around %8 – 9 battery consumption in an hour, and more in cold weather. Battery percentage of Fenix 6X Pro, dropped %10 after about three hours bike ride, which I couldn’t believe.

Ther are many tiny chips around the motherboard. These are different sensors etc. but I couldn’t find information about them. So I’m skipping them.

Around the board there are many holes with spring rods attached to one of them. The rods are GPS antenna contacts I think. In older models there were three springs on the board that touch the GPS antenna. However, on this design they’re placed on different parts of the board and watch. Each rod touches a metal silver paper thin part on the bezel.

Here, you can see a track coming from the GPS chipset and going to the spring rod after passing from some tiny components. Art, isn’t it? 🙂

Backside of the Garmin Fenix 6x Pro motherboard.

A view from the backside of the motherboard. Here, we see a black sticker that’s isolating the parts of the board. There are spring pins to connect the board to charge and data pins on the outer case.

Garmin Fenix 6X Pro battery.

When we remove the motherboard from the case, we’re left with the casing that holds some other parts. We see the big battery that enables it to survive for 80 days. It’s a 420mAh, 3.8V, 1.596Wh Li-ion battery by Routejade Inc. Model number is 361-00126-00. It has 10mAh less capasity then the Fenix 5X battery. But newer hardware with better software optimisation, makes the watch live more. Additionally, battery pack is assembled 5 months before the purchase.

I didn’t try to remove the battery or I don’t remember if I did. I think it’s held by some glue or tape below it. I don’t think it’ll be impossible or very hard to take out if you need to change it one day in the future.

Near the battery, we see the connection terminals of the USB charging port. Pins on the motherboard touch here, and transfer energy and maps or music data. I don’t know about the silver pin. Maybe it’s going to the metal backside to earth the watch! I really don’t know. I should remember to test next time.

In the other side of the battery, we see the vibration motor and the barometer sensor. Vibrator seems to be glued in its place. There are some complaints in the Garmin forums, saying after some hard usage, vibrations start to buzz louder. Probably, glue is dismantled and vibrator starts to move in its place and makes buzzing sounds. I don’t have this problem. Yet… 🙂 Barometer unit is near the vibrator, bolted to case with two screws. I didn’t unscrew them, as I like the watches waterproof. This units takes air from the holes between the start and back keys and measure the air pressure. That pressure reading is put to some calculations and elevation data is produced. Usually a termometer is needed too, but I don’t know where it is. Maybe the sensor measures it itself, or it’s measured by some other IC inside. For example, that Apollo 2 MCU has a thermometer sensor. Or it’s maybe hidden somewhere else…

There’s a tiny antenna on the case. It’s Bluetooth and WiFi antenna I think.

Now, let’s turn to the first part I removed from the watch, the watch crown or bezel. The display is glued to the bezel and covered with a black sticker or sth. like that. NFC antenna is probably under that sticker. I can’t read anything about the producer or the model of the display. Around the bezel, there is the black gasket that prevents water going inside the watch. If you need to open the watch to replace battery etc. don’t forget to clean it from dust and tiny hairs. Otherwise, you can see bubbles instead of your timing when you finish your next triathlon. Also putting some cream or vaseline is good to have some more waterproofing. Four silver parts are where the metal rods on the board touches. GNSS antenna seems to be put on or inside the bezel someway.

Display connector ribbon has many lanes in its both side.

Some more pics to watch during your dreams.

Garmin Fenix 6 series are a nice update to the Fenix line. They have different options for different price ranges. Garmin Fenix 6X Pro has a bigger display, more storage, music capability, blood oxygen sensor, newer and better software with better animations, better battery life etc. Fenix 6X Pro Solar even has solar charging. However, they do mostly the same job that Fenix 3 or Fenix 5 series or even did. But they continue to have increasing prices. So it’s consumers job to think what they need and buy the watch they want. This was just an internal look to a watch with definite external beauty.