ALLPCB
Overview
This teardown examines the Apple Watch SE 40 mm GPS model, which does not support cellular. The front uses a 1.57-inch LTPO OLED Retina display without an always-on function. The back is a single-piece sapphire crystal shell; the heart rate sensor window and LED layout match the Series 5.
Display and front assembly
The display is a 1.57-inch LTPO OLED Retina panel with a resolution of 324 x 394. The cover glass is Ion-X glass. An NFC antenna coil is attached to the rear of the display, and the module contains an ambient light sensor. During disassembly, the screen-to-body interface revealed no haptic feedback coil; instead there is a thick waterproof sealant that fills the step gap between the screen and the case and enhances water resistance. Three flexible printed cables extend from the mainboard and connect to ZIF connectors on the back of the display.
Internal layout and mechanical components
The internal layout is very similar to the Series 5. The rectangular linear actuator at the top is secured with two screws and a metal bracket on the left for reinforcement. The actuator connects to the mainboard via a BTB connector. To the left of the actuator is a metal antenna assembly fastened with a screw, connected via an RF interface.
The battery is secured to the mainboard with foam adhesive and connects via a BTB connector that is reinforced with a metal plate and screws. The unit uses a 3.85 V, 245 mAh lithium polymer battery, model A2227, in a silver aluminum enclosure. This is the same battery model used in the Series 5.
The left side of the case houses the speaker and barometer module. The module includes a waterproof silicone gasket; the barometer sits to the left and the speaker to the right. The right side contains the microphone and button flex, secured by a microphone clamp and a metal press plate. Metal bars at the top and bottom secure the mainboard; four screws fasten the mainboard, case, and bottom cover together. The crown and side button flex connect to the mainboard via BTB connectors. The mainboard also connects to a lower heart rate subboard on its rear.
The bottom cover can be separated from the case by gently pressing outward; the two band release buttons will fall out during separation. Because the GPS-only SE does not support cellular, no antenna components are present inside the bottom cover. A black plastic cover secures the bottom sensor board; it includes a rubber pad on the front and is fixed with a small amount of double-sided tape on the back. A waterproof gasket circles the lower assembly. A ring of magnets surrounds the bottom board and a stainless steel plate sits above; a large magnet is under the plate.
Heart rate board and charging coil
The heart rate board and charging coil are fixed to the bottom cover with foam adhesive. The sensor window in the bottom cover contains a lens. The charging coil housing area is significantly larger compared with Series 5, and there is a translucent plastic shell beneath the coil that isolates the black flex circuit under the coil. Because of differences in functionality, the SE heart rate board is missing one chip found on the equivalent Series 5 board.
The digital crown assembly uses the same mechanical structure as previous generations, but since the SE does not support ECG, the crown flex on the back lacks the ECG-related chip.
Mainboard packaging and major ICs
The mainboard still uses an SiP resin package. Major components identified on the mainboard include:
- BOSCH BMI282 — 6-axis accelerometer and gyroscope
Major components identified on the rear of the mainboard include:
- Sk Hynix — 1 GB DRAM + 32 GB flash
- Apple S5 — dual-core application processor
- Apple W3 — wireless, Bluetooth, and GPS
- Broadcom — custom SoC
- Broadcom — wireless charging management IC
- Broadcom — GPS chip
- Dialog Semiconductor — power management IC
- Dialog Semiconductor — additional power management IC
- ALPS — 3-axis compass chip
Summary
The Apple Watch SE teardown is relatively straightforward, but reassembly is difficult. The design largely follows the Apple Watch Series 5 in appearance and hardware layout, with some functional omissions reflected in the charging coil, heart rate flex board, and crown flex. The waterproof design and removal of the haptic feedback coil result in a thick layer of sealant between the screen and case that serves only as filler and a seal.
Because this teardown unit is the GPS-only version, the device does not include an eSIM, modem, or related RF components for cellular connectivity.
