[LeEco Le Max 2 Guides, News, & Discussion] TheLastCanadian:
PREFACE

So, I figure I'd type this up for posterity in case anyone else wants to perform this repair. If software has not resolved your FP issues, there is a pretty good chance it falls to a hardware problem. Thankfully, once you've dealt with the screen, this phone is actually mercifully easy to repair. As there are no guides in English I was able to find, I decided I would take pictures as I did this (no way to setup a useful recording, sadly) and do a bit of a write up with some instructions and my experience doing it. If you already know how to do this sort of thing - you can probably skip past this, it's not terribly enlightening. For those doing it for the first time or as a novelty, however, I suspect you'll be pleased to have some degree of guidance in a language you understand.

In terms of how this is going to work:

Throughout the guide I will be posting the unedited images and additionally images with colour overlays on them. Please do not take these as absolute gospel as I'm working from memory, particularly in regards to screws. I will reference colours when I refer to specific components, screws exempted for obvious reasons.

Please at least take a quick scan of the guide before commencing work. I know I'd have appreciated it if the portuguese tutorial I was forced to follow on YT hadn't skipped much of this information. It added extra trouble for no good reason. Plus, it's good to do this because it lets you frame each instruction in context, and avoid silly mistakes.

And while I wish I didn't have to say this, here you have it.:

<Standard Disclaimer>

You're doing this yourself, of your own volition. I am not an expert and I do not represent myself to be. My only prior experience is repairing iPhones at a red-themed office retailer. Don't expect much. I am giving you a rough guide on how to do this which you may choose to follow or not to varied consequences. I do not assume any liability for any damage or mistakes, even if such should come from errors in this guide. Basically, if something goes badly, leave me out of it, I assume no responsibility for it whatsoever. Be safe, use common sense, and don't force anything you don't think should be forced. If you don't feel comfortable doing this, don't. It's not hard, but it is easy to screw up.

This project may well violate your warranty depending on applicable statutes. And inapplicable ones - let's be honest, I don't think any of us bought this expecting full service. If you break the warranty sticker, you will almost certainly be denied should anything go wrong in the future, irregardless of cause. It's going to China, so.... don't expect them to humour you when you mention that warranty is supposed to be based only on actual provable damage. Blah blah, if you're looking at this you already know that. In sum: consider your warranty to be null and void.

TOOLS

Note: All prices given in CAD. Shipping not included. No affiliate links - I'm literally just saving you time on the search. This stuff is all based on things I've used, so it's solid enough for the price.

First things first, you will definitely want to ensure you have some very basic tools. You can find most of these extremely cheap on Aliexpress.

1. Watch Tools Screwdriver, specifically Phillips ( + )

2. Suction cup

So, very basic, but you can either use just the generic kind with the metal loop for pulling - this is what comes in the kit I will link below. Alternatively, you can use a clamp-style one (like this ($4.38)), which I would probably suggest as it allows you to use it like a handle when holding the screen and avoids touching near the back of the screen.​

3. Narrow flat things; guitar picks, etc.

Ideally, these should be made out of a material with a bit of give, like plastic. You won't have much travel room between the edge of the phone and the sensitive part of the screen when opening it, and metal will possibly do some damage if you screw this up. I unfortunately have some minor damage on my screen now. More on that later.​

4. Spudger/Flat implement like a Slot Screwdriver

There are lots of flex cables with their caps, along with some narrower parts that could use a gentler plastic tool for prying them off. Prying is a strong word - they're designed to come off readily, but still.​

If you need these tools, a cheap kit can be had at a solid price here ($12 CAD as of posting)

It does come with some other stuff, but I didn't really find those to be useful. Check the listing for a full accounting.

5. Heat Gun/Hair Dryer

Get a heat gun - this project actually benefits quite a bit from having a solid supply of heat. A hair dryer could probably do it, but it costs about the same, so.....​

6. ADB/Fastboot

It seems that you need to load EUI in some capacity (aka, the stock OS) before the FP sensor will take. It needs at least one calibration done from the EUI rom, after which point I was free to flash it. Currently using AOSPEx 8.1 on the D66 modem. If you, inexcusably, do not have ADB or Fastboot, I would recommend downloading it here. For other tools of this nature, search the XDA forum for this phone. It's not that hard. Thx.

Extras:

Heat resistant gloves

You could probably use like gardening gloves or something for this. Basically, the phone frame is metal. Metal gets hot quickly, and more than once during this did I pick it up and recoil because I forgot about that. Having gloves that let you manipulate it while its hot would probably be much to your benefit.

If you want a clamp style suction cup for this project, it can be had by searching "suction tool phone" or at the link, here ($3.29 CAD as of posting).

Not required, but I would very strongly recommend a working mat with magnetism. One solid option w/ dry erase marker surface available here ($7.96)

Screen/repair adhesive. None to recommend, as I opted for the cheap route, but if you do this properly and carefully the adhesive will still be perfectly sufficient to put the screen back in without adding any more. If you want professional/clean, however, you may wish to consider getting a decent tube of this stuff.

PART(S)

Only one. You'll need a fingerprint scanner!

This is the one I used, this is a recent repair though, so YMMV. See the link here ($6.73) only 12 days from China to my front door here in Canada! Not bad.

INSTRUCTIONS

Alrighty, so into the meat of it then. Please be very careful to be deliberate about doing this repair. As I said, once the screen is off, the rest comes fairly easy, but that first part is the real challenge here, and you don't want to mess up if you can avoid it. New screens seem to go for about $30 with shipping on Aliexpress, though, should you need it.

Some updates:

- Do be careful with that screen. Sadly I seem to have been a little hard on mine and cracked something. It's now.... spastic. New screen arriving soon though, I'll post that too.

- I'd wear gloves doing the screen thing, even just standard latex ones. They won't help with heat, but you really do not want to be touching the back end of the screen if you can avoid it.

- The FP sensor is still working quite nicely, at least! Seems like the repair took. [07/14/2018] Still working fine, survived several AOSPEx updates.

Also, a critical note for newbies: DO NOT STRIP THE SCREWS. If they are not coming, they are not coming. Maybe try some heat first or something. But as far as fixing a phone goes, the single worst thing you can do outside of obviously breaking it is to strip a screw, because that basically necessitates the first thing, AND YOU DON'T WANT THAT. Happened on my first iPhone repair, and we had to smash the screen (thankfully that was what was being repaired) to get the screw we needed out. It's serious, do not force the issue.

Part 1: Prep

1. Delineate an area you can work in, with some space. Later in the repair you will likely need space for your screen, your fingerprint scanner, the metal backplate, and the upper motherboard, along with screws, tools, etc. Allow space to SAFELY set down the heat gun, as it will be hot and you don't want things burning your house down or damaging other items in your workspace.

2. Get all your tools you will need close and nearby. Nothing sucks more than having a screen you need to hold attached to the phone while your pliers are across the room. Or whatever. That didn't happen, but yea, keep your tools close.

3. BACK UP YOUR DATA. Sudden data loss is not an expected result of this repair, but it is always possible, and you should be backing your stuff up anyway.

4. Remove your SIM tray and sim cards. Put these aside.

5. Power off the device.

Part 2: Removing the Screen

WARNING

- DO NOT TOUCH THE SHINY BACK PART OF THE SCREEN. OR WEAR GLOVES, BUT YOU SHOULD STILL TRY AND AVOID TOUCHING IT.

- IF YOU ARE USING A MAGNETIC MAT OR HAVE MAGNETS, DO NOT PUT THEM IN CONTACT WITH THE LCD SCREEN.

- The screen is fairly fragile and has limited flexibility

- Do not use the heat gun directly on the screen. It's a great way to kill pixels.

- This phone does not use screws that are all the same size, but they do share thread widths. To avoid possible damage, make certain to remember or note where each screw came from.

- The metal frame gets HOT QUICKLY. You should wear gloves or otherwise be careful touching the phone after using the heat gun.

- Do not use the heat gun on its high setting. You should be able to get your hand about 1.5' to 2' away before it starts to feel "burny".

- Most entry space into the phone is around the bottom capacitive keys. DO NOT GO IN FROM THE SIDES OR TOP, UNDER ANY CIRCUMSTANCES.

- Try to stay vertical, and do not go too deep with the picks

Continuing On:

So you know where you're putting your tools, here's what the back of the screen looks like:

That blue area is the shiny part (I lifted this from a seller's listing, it's protective film). This matches almost exactly with the margins you see on the front side of the screen. No touchy this part. The chip at the lower end seems to be for the capacitive keys. Be gentle when you're getting the screen off. There's more room at the bottom, but you don't want to damage anything. Nothing else of interest really. The narrow side margins in particular are why I say to avoid sticking the pick under the screen; try keeping it perpendicular.

1. Use the heat gun around the frame of the phone, for a while. Give it controlled bursts and be careful not to damage the screen, keep it moving and don't focus long in one place. If you see any distortions forming, STOP.

2. Focus particularly on the bottom; direct most of the heat toward the frame, rather than the screen. There is lots of adhesive on the flipside, and it needs to be fairly warm before it'll be compliant.

3. At the BOTTOM (Side with Capacitive Keys + Charging Port) of the phone place your suction tool of choice. The phone should still be warm to the touch, if you can keep it a bit warmer and have gloves, all the better.

4. Start pulling away from the main phone body with the suction cup on the bottom of the screen. You should see it start raising up from the frame, first some grey, and then black space.

5. Take your narrow implement (guitar picks, etc.) and ON THE BOTTOM SIDE, start to gently pry along the edge. It should be coming up - make sure that you've heated all the sides of the phone though.

6. Once you can get the pick fairly vertical, (facing toward the back of the phone, perpendicular to the screen face), start SLOWLY inching along the sides. Be careful not to let the screen re-settle for the parts you've already finished - I'd keep extra picks on hand for this.

7. Apply heat as needed and slowly inch around the perimeter of the phone. Try and avoid the urge to pry upward - there isn't a lot of space between the sides and the sensitive area of the screen.

8. It's glue, so the screen will feel like it's sticking in. Pay attention to the screen to make sure it's not warping, but otherwise, pry it as required. It should come off without *too* much trouble, make sure most of the work is coming from the suction tool.

9. Only lift the screen up a bit - it has a flex cable attaching it to the main body you'll have to deal with.

10. Remove the screws holding in the metal plate above the end of the flex cable. Take off the plate, and using a FLAT item, such as the spudger pictured above, gently pry away the connector. It should not require much force at all. See image:

Set your screen aside, SAFELY, and again, DO NOT TOUCH THE SHINY PART

NOTE: DO NOT TAKE THIS AS GOSPEL, but I filmed it when I replaced my screen with a new one due to damage I caused trying this the first time around. Read the instructions, don't just watch the video.

[YOUTUBE]ESyCFsGoPrM[/YOUTUBE]

Oh.. and a spoiler, I won't be back with the installation, because I forgot to record that xD

Part 3: Removing the Metal Back Plate

Congrats! You've made it through what is arguably the hardest part of this repair.

WARNING

- Screws are of varying lengths. Ensure you keep them where they belong and use the same screw for the same slot.

Continuing On....

1. See the light blue dots in the diagram below. Remove these screws.

Note: You will see a screw about 2/3 from the bottom on the right that is slightly sunken from the others. This is for the part holding the buttons in place - it will not obstruct your work, so I would suggest not removing it.

Note: The screw surrounded in red has been cleverly hidden under a warranty sticker, at least in the x829. Poke into it, unscrew, and revel in your freedom.

2. Note the small red thing in the top left area, to the left of the camera. This has a flex cable, but it is threaded through a hole in the metal plate. Be nice taking the plate off, and push it out through that hole. We can get it back in later, easy.

3. Provided you have removed all applicable screws (and confirm this visually - I may have forgotten some), you need to lift this plate off the phone. I would suggest (gently) putting the spudger into that squarish hole toward the bottom left and using it for some leverage.

4. Metal plate off. Excellent. Proceed.

Part 4: Removing the Mainboard

No real warnings here. Basically, there's a lot of flex cables, you'll need to unhook them from the mainboard. Some screws too, at which point the mainboard should come off easy peasy.

Note, you are only working in the upper half of the phone. Don't go pulling anything from the bottom half.

Diagram (note, I'll probably reference these colours when referring to stuff):

Unedited:

Do not remove the screws from orange. You don't need to remove this part, and honestly putting the buttons back in properly is a PITA, so just don't. Note: in future images this is missing, because I accidentally did. Do not do that.

To remove flex cables, find the metal cap and GENTLY pry it upward and off. You should not be using much force. Good order:

1. Remove red (lower mainboard) and yellow (battery)

2. Remove blue (this is the antenna! Be gentle. Don't do it so hard it comes out of orange, you'll see it's sort of locked in there).

3. Remove green (buttons panel)

4. Remove Light-blue (fp scanner. This cable wraps around underneath the board. You'll see.)

5. Magenta - you can remove this if you want. It's that thing I mentioned threads through the backplate previously.

6. They're somewhat blurry in the image, but notice the two pink spots. These are screws that need to go. You will also need to remove any remaining screws from the very top of the phone, by the camera assembly.

7. Good, once the screws and flex cables have been removed, try and find a point of leverage (careful of the battery!) to lift up the board. It should come off totally. Per usual, be gentle. This is purely because our fingers are fat and we probably can't grip it well enough that way.

8. Place the board aside. We're going to be whipping out the heat gun again, and the last thing we want is our camera near that. Keep the camera on the board, don't remove any plates.

Part 5: Removing the FP Scanner

Excellent! Almost there!

Basically, the FP scanner has lots of adhesive on it, so get things hot. Most of it should probably be done from the back of the phone, but you'll wanna heat it a bit from the inside too. BEWARE THE BATTERY. BATTERIES LIKE TO EXPLODE IF THEY GET HOT OR COME FROM SAMSUNG. TRY TO AVOID THAT.

Once you've got enough heat, using a clever combination of scraping (a razor blade would probably work nicely here) and pushing through the FP sensor on the back (since it's just held in with now-weakened glue) should get the thing out.

Your phone should look like this. Keep in mind I removed that button cover at right. Don't do that, but just so you don't freak when yours is still there (it is re-attachable, but it's a PITA, so just don't). You're good. Breathe.

Hurrah!

Part 6: Putting in the New Scanner

I think common sense dictates this part, but it is technically the crowning moment, so....

Basically, the one you got from your supplier of choice should have a bunch of tape on its outward (aka, toward the spot you press, back of the phone location) face, and a little more on the actual scanner. Remove these protective films, carefully orient the scanner so it matches the pre-removal picture above, and then press it in and let the adhesive do its thing. The squarish bit on the blue (not light blue) should stick down slightly. You could always use some basic adhesive or something, but it's really not a problem.

Part 7: Putting it Back Together

So, I'll skimp a bit (do ask if you really need me to expand) on this, as it's basically just this tutorial in reverse. However, I do feel it important to mention a few notes so it goes smoothly for you.

- The FP scanner wraps around onto the mainboard; make sure you've got it through when placing the board.

- The battery (yellow) and lower-mainboard (red) connectors really like to get underneath the mainboard as you're sliding it back in. Maybe use some tape or something as a temporary measure to prevent that.

- I've found sliding the board in from the left-bottom toward the right-top seems to work well. Be careful of the buttons flex connector (green). It really likes getting trapped in there - keep in mind it goes ABOVE the board.

Provided you've gotten the board put back in properly again, screw it in, and mount the flex cables.

The general trick with these is get them close to the location. Try and press them in (nicely!) with your fingers until you get a click. If you do, use the spudger and sort of press along its top like you would on a zip-loc bag or such. They should all click right in. Make sure they're all attached before going further. You may need some pliers for putting the antenna back on. It basically just squeezes onto the little peg you took it off of.

Once the mainboard is seated, push the front-facing camera a bit to make sure it's stuck cozily in; if you took it off, at this point make sure to reattach the proximity sensor (magenta in the cable diagram). It'll feed up through a hole in the top leftish area of the metal backplate. Once the plate is in place, push this around a little too, it should be like the camera and fit cozily in.

For the screen, Try it out before putting the backplate back on, just to avoid anything stupid. Once it's good, take it out, put the backplate on (careful of the proximity sensor! Make sure you thread it through the hole as you're doing this), and put the screen cable back in.

Careful with the orientation at the bottom - I sort of don't get such great LED on the capacitive keys anymore. It's probably a bit misaligned. You may wish to heat around the edges of the phone fairly briefly just to make the adhesive stickier again.

Screen on!

Part 8: Software and Getting it to Work

Provided it's not a bad scanner (factory defect when it was sent or something) you should have a working scanner.

Depending on your software, particularly with custom roms, you may not feel like it. That's OK. What you need to do is:

BACK UP YOUR DATA (I told you! See! I told you!)

Flash one of the EUI stock roms. Wipe all data on the phone.

Skip through the setup, and go into settings. Clean your scanner, and click "Calibrate Scanner" in the Fingerprint and Security menu. Try setting up an FP. IF it works, wonderful! If not... well.... hopefully your scanner you just bought isn't bad. I don't really know much about this part of things, so... you're on your own. Let's assume it works. Positive thoughts.

Once you've done this and you've successfully added/tested a fingerprint, you should be at liberty to flash what you like - provided it's not what killed it in the first place. I'm using AOSPEx 8.1 at the moment, and the FP is actually more responsive on that than stock EUI.

Follow rooting tutorials and stuff for this part. I've already written enough.

END OF GUIDE

I hope this helps anyone looking to replace the scanner. Let me know if it can be improved or I'm missing things/clarifications. If you need additional assistance there are tons of Hindi or Portuguese repair guides on YouTube that you can at least follow in principle. If you speak either of those languages fluently, probably best to use those instead of this guide as those people seem to do it for a living. There are tons of offers for parts on Aliexpress, so just look through and pick something that looks good - make sure it has plenty of feedback though, and actually read it where possible.

Good luck!