S3 Cellular Screen Repair

[tradegon]

Can I replace a series 3 cellular screen with one from a series 3 GPS Only watch? Isn't there a special antenna inside the screen on the cellular models?

[cgordon]

The cellular antenna is part of the wifi/bluetooth antenna. (Look at the antenna assemblies on the LTE and GPS S3 watches; you can see they're different.)
The only antenna on the display is the NFC.

You will have to move the Light Sensor module from the old display if you want to use Apple Pay. Use conductive ink/glue to connect the two antenna points under the module, then superglue to give it strength.

Remove the module using something like an xacto #17 blade, then attach with glue. No heat for soldering/desoldering! That way you don't fry the OLED.

[tradegon]

Damnit... So you can't just disconnect the screen assembly from another watch and replace it...

Do you have a picture of the light sensor module?

Thanks for your help.

[cgordon]

Sorry can't post photo.

If you're looking at the back side of the display there are three modules with connectors along the top; they go: OLED, Digitizer, Light Sensor. The Light Sensor module also contains the NFC IC. You can see the modules are each on a separate PCB that's attached to the display.

There are 4 or 5 spots of adhesive and 2 spots of solder (like BGA balls) attaching the NFC module. Just chisel through them with a blade. A little scary the first time but lucky for me I have hundreds of broken displays to play with.

[tradegon]

Originally Posted by cgordon

Sorry can't post photo.

If you're looking at the back side of the display there are three modules with connectors along the top; they go: OLED, Digitizer, Light Sensor. The Light Sensor module also contains the NFC IC. You can see the modules are each on a separate PCB that's attached to the display.

There are 4 or 5 spots of adhesive and 2 spots of solder (like BGA balls) attaching the NFC module. Just chisel through them with a blade. A little scary the first time but lucky for me I have hundreds of broken displays to play with.

I appreciate the info. Sounds like an easy job for the hot air station.

[cgordon]

DON'T use hot air!

You will toast the OLED if you use enough heat to melt solder. This is why I used conductive ink to reassemble.

[tradegon]

Originally Posted by cgordon

DON'T use hot air!

You will toast the OLED if you use enough heat to melt solder. This is why I used conductive ink to reassemble.

Ok lol.

What brand of conductive ink are you using?

Also I assume after all this it still needs a software reflash.

[cgordon]

I don't think it matters much what kind of ink you use. I used some leftover copper ink from this rear window defogger repair kit because I had it lying around. You just have to be careful to use a tiny amount so that it doesn't goosh around and short things out.

Weirdly enough, after I put on the replacement display the force touch didn't work. After I reflashed, then force touch was working. So yes, you should reflash after repairing.

[tradegon]

Originally Posted by cgordon

Sorry can't post photo.

If you're looking at the back side of the display there are three modules with connectors along the top; they go: OLED, Digitizer, Light Sensor. The Light Sensor module also contains the NFC IC. You can see the modules are each on a separate PCB that's attached to the display.

There are 4 or 5 spots of adhesive and 2 spots of solder (like BGA balls) attaching the NFC module. Just chisel through them with a blade. A little scary the first time but lucky for me I have hundreds of broken displays to play with.

https://imgur.com/ymN4sQc

Is this the module that needs to be removed outlined in blue?

[cgordon]

That's the one. You get a prize!

[tradegon]

Originally Posted by cgordon

That's the one. You get a prize!

Wow you are like the Watch Wizard lol. I never saw anywhere online about this.

Just curious, other than a curved blade, is there an easier way to pry off the screen and preventing scrapes and such? I'm already using a bit of heat.

[cgordon]

I put a piece of Kapton tape along the top edge of the watch, then set my hot air tool at 200°C and heat the display. Then I use the curved blade; the tape protects (not perfectly) the finish on the watch from getting scratched up.

If the display is badly broken, I don't use heat at all. I put isopropyl where the glass meets the metal, then take it off in pieces. Only ever use anhydrous isopropyl, or at worst 99%. I work it gently with a blade I made by grinding an xacto 17 down to ~1mm wide. The blade is beveled on one side and flat on the other; if you keep the flat side against the force touch sensor and keep the blade nearly parallel to the sensor you'll minimize damage to the sensor.

And I'm not a wizard -- I just have the advantage that I have buckets of "scrap" watches so if I try something and it goes sideways I just say "lulz" and toss it. I don't have to learn on customers' watches or stuff I bought to flip.

[clayp00l]

So to get this all straight

1. Apple series 2 Lcd assembly works on both?

Apple watch Series 3 LTE/GPS
Apple watch Series 3 GPS

You just need to transfer the daughter board and reattach it to the to points on
circuit flex + and - ?

2. Does the series 2 screen thats being used have to be updated to the current os ? for example if the new apple series 2 lcd assembly was paired with os 3 and
the watch your repairing is on OS 4 does this matter will a restore fix it?

3. Assuming all this is correct , I am guessing series 2 glass / digitizers are good for 3 LTE and 3 GPS?

4. Do the sensor gaskets from series 2 work on series 3 LTE model?
I realise 3 GPS is different

thanks

[cgordon]

Originally Posted by clayp00l

So to get this all straight
1. Apple series 2 Lcd assembly works on both?
Apple watch Series 3 LTE/GPS
Apple watch Series 3 GPS
You just need to transfer the daughter board and reattach it to the to points on circuit flex + and - ?

Correct.

2. Does the series 2 screen thats being used have to be updated to the current os ? for example if the new apple series 2 lcd assembly was paired with os 3 and the watch your repairing is on OS 4 does this matter will a restore fix it?

I've seen some situations where the Force Touch didn't work after a display replacement, but after reflashing it worked. This doesn't make sense to me but I've just made it a habit to reflash after any display replacement, regardless of series.

3. Assuming all this is correct , I am guessing series 2 glass / digitizers are good for 3 LTE and 3 GPS?

I've done GPS and LTS, so yes.

4. Do the sensor gaskets from series 2 work on series 3 LTE model?
I realise 3 GPS is different

No, they don't fit.


Also, an update: I've gotten some Z-tape to play with, and this works for both the electrical connection and the mounting. It's way easier than conductive ink and superglue. The light sensor will probably work through the Z-tape, but I trim around it and leave the sensor uncovered just to be sure.