Gordon Hlavenka

I have successfully swapped a S2 Display onto a S3 Watch. I removed the Light Sensor / NFC Module from the damaged S3 Display and attached it to a working S2 Display. I used conductive ink to make electrical connection to the two antenna points under the module, and superglue to mechanically attach the Module. Next I reflashed the Watch firmware using a (non-Apple) hardware device similar to the one used at the Apple Genius Bar. I verified NFC functionality by setting up Apple Pay on the Watch, double-tapping the Side Button to activate Apple Pay as though I were about to make a purchase, and reading the "tag" data with an app called "CardTest" on an Android phone. The repair is a little bit fiddly but doable.

IO - No, the ipsws on ipsw.me and similar sites won’t work. They are over-the-air update files (“OTA”) and do not contain a complete set of code including boot loader and all modules.

viarengo1 - The tricky part of reflashing is actually just getting the IPSW files to flash — OTA update files don’t work and Apple doesn’t release the complete files. If you can manage to get the file, though, you connect the Watch to a programming adapter (either iBus or the Apple adapter), load iTunes, and the Watch shows up. Then you shift-click on Restore, point to your hard-won IPSW, and off you go. You can sometimes find Apple programming adapters on eBay and MFCBox sells the iBus, which is a clone of the Apple adapter. But the IPSW files are a major PITA. Right now I don’t think any of them are in the wild except WatchOS 4.3.1 for Series 3 only.

I’m not sure what the issue is; sometimes I noticed that Force Touch didn’t work after a Display replacement (?!) and reflashing made it work again. But sometimes reflashing wasn’t necessary. Since I had the iBus, I just reflashed as a matter of course. There seem to be some dark ninja-like corners to the Apple Watch firmware.

Michael I used the iBus tool + their “Dongle” software. Occasionally iTunes-compatible files are available that don’t require the Dongle but not at the moment.

Update:

I’ve received the widget and now updating the watch OS takes 15 minutes instead of an hour+.

I had several Series 2 watches that worked after a display (digi+OLED) replacement but wouldn’t pair after a reset. My theory is that the code on the digitizer IC has a compatibility issue with the watch OS… Using the widget, I reflashed the watch OS and now they pair.

The sequence was thus:

1 - Watch pairs and works but has broken glass. Do not reset yet.

2- Replace display (digi+OLED assy)

3- Watch works.

4- Reset watch. Watch will not pair.

5- Reflash OS using widget. Watch pairs.

I don’t think the digi and OLED are linked. Rather, I think the digi IC contains code that must be compatible with the OS version on the watch itself. We bought displays that were advertised as tested and they did in fact work, however watches wouldn’t pair after a new display was installed. Reflashing restored the ability to pair. It’s possible there’s also code on an OLED driver but a reflash fixes whatever is causing trouble.

I’ve moved display assemblies between S2 watches without any reprogramming. Haven’t bought any new parts for S2 though.

I have access to a quantity of broken Apple Watches I can experiment on. Here’s what I’ve discovered:

- Heat is not needed to separate the OLED and digitizer. Isopropyl alone does the job just fine. Series 2 uses a beefier OCA than Series 1 so you have to go a bit slower.

- Most of the OCA stays on the OLED when you separate it. You have to be gentle removing the OCA from the OLED; if you press too hard you will damage the OLED.

- Bonding the OLED to the digi with LOCA and a UV lamp takes two minutes, tops. I’d never used LOCA before.

- The digitizer is not “paired” to the OLED. I took two of them apart, swapped the digitizers, and they still worked.

- I installed a virgin digitizer on a Series 1 watch and it didn’t work. Then I updated the OS on the watch (from 3.2 to 4) and the digi worked. Updating the OS was by far the most time-consuming step in the process.

- I have ordered a widget that connects the maintenance port to a Lightning cable; this is supposed to allow faster DFU-updating the OS in iTunes.