Samsung Galaxy Watch4 & Watch4 Classic
What makes it tick.
Samsung recently unveiled two updates to its smartwatch line in the Galaxy Watch4 and Galaxy Watch4 Classic. Though externally similar to last year’s Watch3, there’s a good chance of internal differences, and we’re here to sniff them out. Time for a teardown!
Major tech specs
• Exynos W920 1.18GHz with dual ARM Cortex-A55 cores, Cortex-M55 display processor, Mali-G68 GPU, and integrated LTE
• Circular Super AMOLED always-on display – 1.19-inch or 1.36-inch sizes (both models) 330 PPI
• 1.5GB RAM and 16GB internal memory
• 361 mAh battery, Watch4 Classic (46 mm). 247 mAh battery, Watch4 (40 mm)
• Sensors, including accelerometer, barometer, gyro, geomagnetic, light, optical heart rate, ECG, bioelectrical impedance sensor, and a Hall sensor on the Classic
• IP68 rating with water resistance to a depth of 50m (5 ATM)
Though the Galaxy Watch4 and the Galaxy Watch4 Classic have almost identical specs, they each rock their own look. The Watch4 Classic is bulkier but has some classy stainless steel or titanium frame options. Both models open up through the back: a specialty driver easily takes care of the four tri-point screws and a quick pry from an opening tool gets us inside.
What we find is: a Samsung package combining the Exynos W920 dual-core 1.18GHz processor with 1.5GB of its in-house LPDDR4, Samsung Shannon 915 intermediate frequency IC, Broadcom BCM43013 ultra low power dual-band 802.11n Wi-Fi and Bluetooth 5.0 combo IC, and likely a Qualcomm Atheros QPA5580 power amplifier. The back of the Watch4 (not the Classic) shows us a couple more of those same chips: S915 intermediate frequency IC and a Broadcom BCM43013 ultra low power dual-band 802.11n Wi-Fi and Bluetooth 5.0 combo IC.
The fuel tanks are hidden under the motherboards, nestled within plastic midframes, and can be removed with the help of a sturdy spudger. The Watch4 Classic accommodates a 1.40Wh (361mAh @ 3.88 V) battery, while the Watch4 houses a 0.95Wh (247mAh @ 3.88 V) battery.
We shake the last components out of the midframe and find a familiar vibration motor next to the barometric sensor. The most interesting part is the button flex cable. It not only carries a microphone but is also equipped with a contact plate opposite its connector. This allows the watch to close an electrical circuit through your body for bioelectric impedance analysis.
The Watch4 Classic prioritises simple display removal. With a little heating, we separate the circular AMOLED screen from the frame with a push. Unfortunately, the standard Watch4 isn’t so friendly. We grab our heating and prying tools and promptly crack the screen. Whoops! At least if you’re prying the screen off, it’s probably already broken. Tick, tock, it’s score o’clock. Our journey through two Galaxies comes to an end.
Repairability Score: 7 out of 10 (10 is easiest to repair). Opening it is straightforward and requires some prying, but no heat. The batteries are easily accessible and use only mild adhesive. With a little heat, the display of the Watch4 Classic can be removed without any additional tools. Only two types of screws are used, although the back cover screws are uncommon tri-points. Both watches are modular, with only the rear sensors being buried inaccessibly in the back cover. The Watch4’s display sits in the frame and seems impossible to remove without damaging it.