Apple Watch Ultra 2 Sensor Assembly Replacement

Written By: Arthur Shi

Comments: 1

Apple Watch Ultra 2 Sensor Assembly Replacement

Difficulty

Moderate

Steps

Time Required

30 minutes - 1 hour

Introduction

Follow this guide to replace a cracked or broken sensor assembly in your Apple Watch Ultra 2. The sensor assembly includes the skin-facing sensors along with the back panel that houses the sensors.

Since the sensor assembly uses screws to compress against the perimeter gasket, you can normally reuse the gasket during reassembly. However, you may still lose some water resistance once you open up the watch.

Tools

Step 1

Drain your watch battery below 25% before starting this repair. A charged battery may catch fire if damaged.
Take your watch off the charger and power it down.
If your touchscreen is broken and you can't power off the watch, use this alternate method to power it down.

Step 2

Because the gap between the screen assembly and frame is so small, a thin metal tool is needed to pry the screen up. Read the following warnings before you start disassembly:
Protect your fingers by keeping them completely clear of the front end of your tool. You can protect your free hand with a heavy glove, such as a leather shop glove or gardening glove.
Be careful not to apply too much pressure, as this might cause the iFlex to slip and cut you, or damage the watch.
Wear eye protection. The glass may break, sending pieces flying.
Attach or remove the watch bands as needed to provide more control as you make repairs.

Step 3

Use a P5 Pentalobe driver to remove the four 2.2 mm‑long screws securing the sensor assembly.

Step 4

Heat an iOpener and apply it to the sensor assembly for at least two minutes to loosen the adhesive underneath.
You can also use a hair dryer, heat gun, or hot plate, but be careful not to overheat the watch—the screen and internal battery are both susceptible to heat damage.

Step 5

Insert an iFlex in the seam between the watch frame and the top edge of the sensor assembly to create a gap.
Carefully twist the iFlex to widen the gap.
Don't apply too much force, or you'll cause the sensor assembly to pop off and tear the sensor assembly cables.

Step 6

Insert an opening pick into the gap you created.
Do not insert the opening pick deeper than 3 mm to avoid tearing the sensor assembly cables.
Remove the iFlex.

Step 7

Slide the opening pick around the top right corner of the sensor assembly and along the right edge to slice its adhesive.

Step 8

Slide the opening pick around the bottom right corner and along the bottom edge to slice the rear assembly adhesive.

Step 9

Slide the opening around the bottom left corner and along the left edge to slice the remaining adhesive.

Step 10

In the following steps, the band release buttons and springs may fall out. Be careful during the disassembly, as they are very easy to lose.
The band release buttons are equipped with a tiny spring on each end. The springs are mandatory for the buttons to function properly.
During reassembly, make sure each band release button has its two springs, and the buttons are repositioned in their recesses.
If a band release button falls out and the springs aren't on the button, they may have gotten stuck in the watch during disassembly. Use a pair of tweezers to remove them from the watch and place them upright into their recess on the button for reassembly.

Step 11

The sensor assembly is connected to the watch body with two cables. One of the cables is extremely short and its connector will automatically disconnect when lifting the sensor assembly.
To reconnect the short press connector during reassembly, line up the sensor assembly to the frame and squeeze gently.
Carefully lift the top edge of the sensor assembly with your opening pick until you can get a good grip with your fingers.
Don't try to remove the sensor assembly all the way yet. It's still connected to the watch body.

Step 12

Be careful not to strain the sensor assembly cable when you lift the assembly up.
Lift the sensor assembly and carefully pull it towards the bottom edge of the watch.
Swing the sensor assembly open to an upward position.

Step 13

The band release button near the sensor assembly cable is equipped with a tiny spring on each end. Be careful not to lose the button or its springs.
Use a spudger to pry and disconnect the sensor assembly cable from its socket.

Step 14

Remove the sensor assembly.

Conclusion

To reassemble your device, follow these instructions in reverse order.

Take your e-waste to an R2 or e-Stewards certified recycler.

Repair didn’t go as planned? Try some basic troubleshooting, or ask our Answers community for help.

Author

Arthur Shi

Member since: 03/01/18

263408 Reputation

One comment

Nice job!

But where can I get a spare sensor assembly for the Ultra 2.
On iFixit it doesn't seem to be available

Would a rear side sensor assembly from an iCloud locked Ultra 2 watch, sometimes offered on eBay, work?

jojo -