TideLog Posts Tagged “screen”

I had the misfortune of my tablet getting damaged this week. I was working in Rikku’s bus garage, with it resting on the bus’s bumper crossmember taking readings from the ECU, when Rik called me away. While I was away the vibration of the engine caused my tablet to fall off, straight onto tarmac! Luckily the screen hasn’t cracked.

I’ll show you all how to replace the digitizer, as it’s a lot more straightforward than also having to replace the screen, as less disassembly is required.

A. Removing the SD card cover/Wi-Fi antenna

First of all, your digitizer is GLASS, so you can use sellotape across the glass to hold it in place, preventing any injury, or shards of glass falling on the floor. Removing the damaged digitizer will stress it and maybe cause more damage as you do it. The glass provides 90% of the front frame’s strength, so once broken it loses most of its rigidity.

Once you’ve secured the glass, turn your tablet over, and remove the SD cover, which also doubles as a WiFi antenna, by locating the notch on the left, and lifting up. It unsnaps quite loudly, but be gentle. Once removed, place in a safe place:

2-removing-SD-cover

B. Removing the rear casing

Next up we’ll be removing the rear case, which is easy to do as there’s no screws, it’s all clipped together. A lot of the reviewers of the Bush MyTablet reckoned the aluminium back was just cosmetic, but it is actually structural, and gives the tablet weight and strength to prevent flexing of the whole body to protect the internals,.

Using a flat blade jeweller’s screwdriver, unsnap one set of clips between the front digitizer frame and the rear case, and then use a plastic spudger to do the rest. DON’T use a screwdriver permanently, only to get a start. Note in my picture below, the lip of plastic on my rear case near the headphone port was damaged on mine in the impact, so I used this as an easy access point for my spudger:

3-unclipping-digitizer-from-rear-cover-1

Continue all the way round the case, and don’t worry about snapping noises. The screen is clipped to the backside of the digitizer, but as long as you are gentle, it won’t resist too much, and you shouldn’t break anything. The glass may crack and crunch on the broken digitizer at this point, due to the lost strength I mentioned earlier. I didn’t use tape on my glass as I was on a disposable cloth I could just throw away:

4-unclipping-digitizer-from-rear-cover-2

Once you’ve unsnapped all the clips, the rear case will just lift off. There’s nothing attached to it, so just lift it clear, upon doing so you’ll see the wonderous internals of the tablet, including the relatively large battery, and small mainboard. You can also see how the aluminium back actually constitutes most of the rear cover, with the plastic just being a small frame, proving my point about the strength the metal back provides:

5-lifting-off-rear-cover

When you remove the back cover, WATCH out for the power and volume button pack dropping out. It isn’t plastic welded or screwed onto anything, so it’ll just fall free:

6-watch-out-for-volume-and-power-buttons-falling-out

C. Screw and connector locations

Now comes the preparation stage of locating the connectors and screws you’ll need to remove. If you’re just removing the digitizer, there’s 2 screws and 2 ribbons to remove, but if your screen is broken most of the internals have to come apart as the mainboard and battery are mounted to the back of the screen panel’s chassis with tape and glue, both of which are surprisingly strong!

7-screw-and-connector-locations

The ribbon cable connectors for the digitizer and display are under the tape on the left and right sides, respectively, which I’ve labelled in red, the two red circled screws attach the PCB to the digitizer frame. The battery and speaker cables are under the orange tape on the bottom left. These two are soldered in, but don’t need to be de-soldered at all unless you are explicitly replacing them. Even for a screen replacement, desoldering these isn’t necessary, they can just be lifted out the way. To remove the battery for screen replacement, simply break the glue holding it in, and lift it out of the way after the rest of the disassembly is done, leaving the wires soldered in. Don’t do it yet, you’ll end up with a tangle!

The connector flaps for the ribbons need to be flicked upwards NO MORE than 90 degrees VERY gently. If you snap the flap, the whole PCB socket is ruined as the flap provides the torque to hold the ribbon in place, pressing the metal contacts together. Taping it back together is not good enough. DO NOT rush, the same goes for the left one. This is where unskilled amateurs make the jobs more expensive, take it from a professional who has fixed mistakes many times! Modern electronics are VERY delicate, and need eagle eyesight and jeweller’s finesse, shaky hands just won’t do!

From the left, lift the silver tape a little (DON’T damage or discard it as it can be re-used), and remove the ribbon for the power/volume buttons. Lift the flap gently, then ease the cable out.

10-power-and-volume-switch-ribbon-connector-location

From the right, lift the black tape. If you’re going to be replacing ONLY the digitizer, remove just the top ribbon that I’ve circled red, which is the digitizer cable, using the same care as for the power/volume ribbon above. If your screen is cracked, you’ll need to remove the bottom one as well, which is your display cable that carries display signals, and the backlight power.

Again, I can’t stress enough, DO NOT rush, and DO NOT force the socket connector flaps over 90 degrees, if they break you’ve just made the job 80% more expensive as you’ll need the sockets replacing, or a new PCB, which will involve data recovery off your old board, especially if you damage the touchscreen connector!

11-digitizer-ribbon-connector-location

D. Removing bottom frame support

Where the speaker is along the bottom you’ll notice a plastic frame screwed into place. This is like a strengthener and support in one unit, it holds the speaker in place while giving the bottom of the digitizer some strength. It also carries clips that the rear cover was mounted to, so I consider it a main structural member of the whole tablet chassis. Simply remove the two screws, and lift it off the digitizer. Watch out as the speaker is now loose on its cable and will slide around!

8-screws for-frame-support

E. Removing screen & mainboard assembly from digitizer

If you look all around the inside of the frame you’ll see lots of clips holding the screen in place. We’re now going to remove the screen VERY GENTLY. This is another step that you should take your time, there’s no medal for rushing it, as you WILL likely break your screen if you do it wrong, the glass on the screen is thinner than the digitizer. That’s the reason tablets have their digitizer separate to the screen, mounted half an inch away.

If your screen and digitizer are already broken and you’re replacing them both, I personally would still be careful, because I’m a professional, and normally it’s someone else’s equipment, which I respect 🙂

9-clips-attaching-screen-to-digitizer-frame

So, while unclipping the clips (they may be stiff) you can use a spudger to keep the screen from re-clipping itself in, but DON’T overdo it, don’t lever the screen too high with too many clips still securing it, it will flex and break. Obviously if your screen is broken and you’re replacing it this isn’t relevant, but still take care, because I would 🙂

The image below shows me using my spudger as the clips are unclipped, my screen wasn’t damaged before, and it wasn’t damaged after, apart from a scratch on the glass caused by the digitizer imploding on impact!

12-unclipping-screen-clips-while-lifting-screen-GENTLY

Finally, once that’s all done, you can separate the digitizer from the rest of the chassis, and pat yourself on the back for getting this far without any major damage, unless you DID damage something I told you not to, in that case it’s your fault for not listening to a pro, take yourself off to the naughty corner and think about what you’ve done!

Otherwise, if all went well, you’ll end up with the tablet looking like this:

13-chassis-and-digitizer-separated

Re-assembly with a new digitizer is the reverse of removal, if you remember my advice you should have a fully functioning tablet that acts as if nothing happened once it is rebuilt!

F. Extra steps for screen replacement

I only had to replace my digitizer, but if your screen is damaged as well, once you finish with the separated digitizer as step E, you’ll need to:

  1. Remove the display cable connector as I mentioned earlier
  2. Separate the battery from the screen back by removing the glue. When you reassemble the battery onto the new screen, use *new* adhesive strips instead of glue to secure it, as you don’t want it rattling around, its metallic case can short stuff out, which you DEFINITELY don’t want happening.
  3. Remove all the tape strips holding the PCB,
  4. If you’re also replacing the battery, desolder the battery cables, making sure you note the polarity. Resoldering the cables the wrong way may short the board out, and cause an expensive mess. I don’t know if the Chinese electronics in these have decent short-circuit protection, and I’m not willing to find out!
  5. Re-assembly, again, is the reverse of removal. With new parts, TAKE EXTREME CARE, you don’t want your new screen or digitizer damaged again! And make sure all the tape is replaced and secured in the original places. Mark out where the strips sit with a marker pen.

Good luck!

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