Come Learn the Secrets of the Finicky Mini
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Bring up the iPad mini in a conversation with the repair community and you will hear a roar of “Oh, I HATE the mini” This device is a booby trap for many—from its sensitive backlight circuit, its prissy taping requirements, and the well-intentioned but misleading how to videos on YouTube. Compound that with an ocean of low quality mini screens flooding the domestic marketplace, and it is easy to see why the poor mini is so hated.
Like many of you, my first mini repair got thrown against the wall. But after learning dozens of lessons from her the hard way, she has shown me all of her secrets. As high maintenance as she is, the iPad mini has now become my favorite device to repair. I have fixed thousands of minis and my little bff no longer gives me any trouble.
I will now share those secrets coaxed from the sisterhood of minis, so that you too can come to enjoy her purse-sized loveliness and repair her without fear.
How to tame the mini and fix her perfectly every time:
I will walk you through an iPad mini screen replacement step by step and point out all the many things I’ve learned the hard way (TILTHW) as we go. Hopefully by following along you can skip over some of these expensive lessons yourself.
Step one: Glass digitizer removal:
This step is straightforward and similar to any other glass digitizer. Apply your favorite heat source and work your way around the mini to free the glass from the frame.
Things I’ve learned the hard way (TILTHW):
If you are dumb enough to use an exacto knife, even though you are “super careful” you will slice a line into the LCD.
Step two: LCD removal:
The iPad mini LCD is deceptively thin, and it doesn’t like to flex or bend at all. To get it out, you’ll need to use two plastic spudgers to gently coax it up off the underlying LCD shield. Just slide the spudgers in on opposite sides to separate the LCD from the mid frame shield and work your way down to the bottom. The LCD will come up, but still be attached at the bottom. You can cut through the cloth tape to free the bottom of the LCD. The two cloth tape rolls at the bottom of the LCD are optional and can be removed.
Don’t lose the 4 LCD screws. Nobody sells these and other screws just don’t fit.
You can unscrew straight through the grey foam adhesive on two of the LCD screws and leave that foam stuck to the screw head—this will help you on reassembly.
If you flex it too much, the LCD will crack or just never turn on again.
A small dent in the sidewall of the frame will snag the LCD as you lift it and crack it.
If you accidentally put your spudger UNDER the big metal LCD shield, instead of between the LCD and the shield, you will use too much force and crack the LCD.
If you have done several mini WiFis, you may not realize that the mini 4G cellular versions have black tape that needs to be cut at the TOP of the LCD/cellular antenna area. If you don’t know this, you will use too much force and crack the LCD.
Step three: Remove the big LCD shield.
These screws are a shade longer than the ones on the smaller shield below. If you substitute one of these screws for the smaller screws you will rip a screw bracket off your board. Do not mix them up.
If you bend the LCD shield, then after reassembly it will cause a lift on the LCD which will translate into an “oil spot” on the screen where the LCD is touching the digitizer.
The wifi and cellular versions of the mini have different LCD shields that can’t substitute for each other.
Step four: Remove the small shield and disconnect the battery.
Keep track of the three screws for the small shield. Do not substitute any other screw or you will pop the bracket off the board, and in the mini retina—tear up the board traces catastrophically
THIS IS A BIG ONE—-Disconnect the battery before any of the connectors. Failure to do so sets you up classically to blow the iPad mini backlight filter/fuse.
Here’s the deal with the iPad mini backlight failure. Having tried to duplicate this many times, I can tell you that you can rip that LCD connector right off, even when the LCD is fully powered on at full brightness and not affect the filter.
Surprising, no? The problem is in the *way* you pull the connector. There is some juice going through the connector even with the iPad is powered off. The LCD connector itself has its hot power pin right next to a ground pin. If you are trying to be careful, you can easily lift off the connector in a way where the hot pin is momentarily shorted to the ground pin. This sudden discharge of voltage will melt the inner core of the backlight filter, aka fuse. After that happens, you won’t have a backlight again until you replace that component. You can *see* the melted backlight filter in classic cases—-there will be a tiny pin prick of solder oozing from the center of the filter. That breaks continuity in the backlight circuit and the screen will not light.
The solution is just to always pull the battery connector first, killing all juice through the connector, and you’ll never get a backlight problem again.
THIS IS ANOTHER BIG ONE—-Pull the battery connector up from the battery side, not the board side. Failure to do so sets you up for a battery percentage/charging problem.
Here’s the deal with the iPad mini boot / apparent “no charging” problem.
The board has two lines of communication with the battery for data. The board gets info
from the battery via the gas gauge line—aka battery percentage, and the NTC line—aka battery temperature.
The gas gauge line extends from the battery and goes through a filter, FL7500, right next to the battery connector and on to the logic chips. If your fingernail flicks that filter off, then when you lift the battery connector from the board side, you break this line of communication.
Once that happens, the board gets no more information on the battery percentage. So the battery percentage will stay fixed and only change at reboot. You will notice that the iPad mini is reporting whatever percentage the battery happened to have when this happened. It will not increase nor decrease. You may interpret this as “hey it’s not charging” but it is charging—-it just doesn’t know it. Any effort you make to replace the battery and solder in a new charge port is a waste of time. The solution is only to replace the missing filter. There is nothing more sad than when I get a mini in that is missing solder pads at the charge port from a hopeful DIY charge port replacement job, and I look over and sure the FL7500 battery filter is missing. It never needed a charge port.
If you see that the mini is telling you that is has plenty of charge—-perhaps a lie, the board has no idea what the actual percentage is—-then you may wonder why your mini begins to boot loop. Apple logo, dark, Apple logo, dark….
Boot looping happens (in this case) because the *actual* battery percentage has dropped so low that it can’t support powering on the iPad. But the logic board doesn’t “know” this. It “thinks” the battery percentage is still high. The low battery logic—-warnings and prompting you to plug in to charge—-do not happen. The boot loop is just the continual effort of the mini to boot off a dead battery—while telling you that the battery is fine.
The solution is again—just replace the FL7500 filter. All the restores in the world will not cure this hardware defect. Worse, if you just plug it in to charge, eventually the boot loop will resolve as the mini charges up. You will then exclaim—Aha! I solved it! It was *insert bogus reason that was the thing you happened to be doing when the mini charged up enough to boot* Aha! It just needed foam on the digitizer! Aha! It just needed the magnets transferred! Aha! It just needed a day in a bag of rice! —-This is how the repair forums of the internet get clogged with mini mis-information.
If you experience any of these problems—look first at the battery connector for damage to FL7500. Better yet, just get in the habit of pulling up the iPad mini connector from the battery side and you’ll never flick that sucker off to begin with.
Step Five: Disconnect the LCD and digitizer connectors and remove the digitizer/LCD.
Yet ANOTHER BIG ONE: Ripping out the gold teeth of the digitizer connector.
Pause and think for a minute before you pull the digitizer connector. More than any other repair, we see iPad minis coming in that are missing gold teeth from the digitizer connector socket. The connector is a simple little thing—built like a McDonald’s toy. It is a cheap piece of plastic holding together a row of gold pins. It is too flimsy to repair, so when it is damaged by, say, a particularly good sneeze—then it must be replaced by your friendly microsolderer. This can happen both on removal of the digitizer flex, and on connection. Once it happens to you, it rarely happens again. It seems that an awareness of its extreme fragility is all you need for immunity to this problem.
Pay attention to the way the original digitizer flex is lying as you remove the flex and touch ic chip. It is bowed toward the LCD and fits snugly in the gap between the bottom of the LCD and frame. It does not have a crease of any kind. It does NOT bend back toward the frame or touch any of the adhesive on the digitizer. On reassembly—you must make the digitizer flex match the original—-or else you’ll be buying a new digitizer when you find that you no longer have touch function due to a crease in your flex.
Step Six: Clean and prep your frame.
This is the key to a professional quality screen replacement vs a DIY job. We use Scotch 3M Sticker remover pens to scrub off the old adhesive, then wipe that off and clean any residue with alcohol. Others use razor blades or just alcohol. It probably doesn’t matter which method you use, as long as you do it.
Next, straighten your frame. There are commercial tools, such as “the G-tool” to help mold banged corners and sidewalls back into Apple original shape. Alternatively a dremel tool can help file down any spots that would keep the digitizer from sitting perfectly flush and square.
If you don’t clean off your adhesive your new digitizer will lift over time.
If you don’t straighten the frame, your new glass will sit on TOP of the frame and create a pressure point. The next day, the mini will be back with a thumb-sized hole in the glass
Step Seven: Prep and install new digitizer, dry fit and test.
To prep the iPad mini digitizer, you must:
1.) Transfer the magnets from the old digitizer to the new. The magnets have no electrical or signaling function despite what the internet may tell you. Their only job is to hold magnetic mini cases closed—-like the popular Smart Cover. You might think this is silly, and be tempted to omit the magnets. You can, and the mini will suffer no functional effects. However, if you think of a smart covered mini rattling around in a purse, with the smart cover flopping open, and pennies and half-melted M&Ms sliding across the glass, you might take the 10 seconds to transfer the magnets to the new glass.
2.) Taping. You must make sure the solder joints on the touch ic/digitizer flex junction are covered with tape. You must also tape over the exposed copper on the home flex, and ideally, the entire bottom of the digitizer if your screen doesn’t have pre-installed cloth tape like the original. Use kapton tape—google this if you don’t have it. Other tapes won’t hold up well to heat and be a gummy mess at the next screen change. Make your new screen match your original screen.
3.) Check your screen for quality. More than any other part out there, it is difficult for the parts distributors to source quality iPad mini screens. There just aren’t a lot of them available. The market is flooded with low quality iPad mini digitizers—-the worst being commonly sold on eBay for cheap to people who don’t any better—yet!
An original quality digitizer will have:
—SMD components on the home flex same as in the original.
—a gold digitizer border, not silver
—pre-installed cloth tape adhesive on the bottom of the digitizer.
—pre-taped home flex
—a quality solder junction at the home flex/digitizer connection.
—a thickness of the digitizer flex and the glass itself that matches the original screen.
—oleophobic coating—it will bead water
4.) The dry fit test. The iPad mini digitizer should have good touch function, fit snugly in the frame and have home button function. But that’s not all. You should also check that the top power button is functioning before you seal the mini—-strange as it may seem, the top power button is routed through the digitizer home flex. Also press around the bottom of the digitizer. The smart cover lock/unlock function is part of the home flex. A poor solder joint on the home flex can inappropriately activate the lock/unlock function when this area of the screen is pressed.
Failure to tape the home flex = digitizer ghosting
A defective home flex = screen will lock by pressing bottom of digitizer
A poor solder joint at the home flex can = no power button function after final seal
Failure to dry fit = not realizing you have a bump in your big LCD shield/shard of glass/“lost”screw that is snugged to the magnetic frame——> “oil spot” where LCD is lifted and contacts the digitizer.
No home button function = you knocked off a tiny required resistor near the digitizer connector.
Step Eight: Final Seal
After the dry fit test, screw in all screws back in the exact spots they came from to secure the small connector shield, the large LCD shield and the LCD. Put on surgical gloves. Pull the backing from the pre-installed adhesive on the screen, or use red tape adhesive. Pull the clear covering protecting the inner surface of digitizer. Use compressed air to blow any dust from the LCD. For any pre-existing marks on the LCD, use just the humidity from your breath and a new microfiber cloth to wipe away. Paying careful attention to make sure the digitizer flex bends toward the LCD, lay the screen down starting by aligning the two bottom corners, then the two top corners. Be sure the camera bracket fits into the camera bracket holder before pushing to seal the digitizer. Apply gentle heat and press all sides to form a perfect seal. I do not find that any additional pressure or clamping is necessary. If you see a lift at the bottom of the screen near the flex, reposition the magnet so the screen sits perfectly flush. Never use any liquid adhesive. The screen will fit perfectly professionally flush without any funky tricks—if not, figure out where you went wrong.
Test. Confirm perfection.