How To Clean Loca From Between The Lcd Screen Layers Sony Xperia Z3 Repair Guide

Difficulty

Difficult

Steps

8

Time Required

                          45 minutes            

Sections

1

• How to clean LOCA from between the LCD screen layers (Sony Xperia Z3)
• 8 steps

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Introduction

Step 1

              When to repair               

• If your screen is flooded by LOCA, and a new one costs more than you’re willing to pay without trying to fix the old one, then this is the guide for you. This screen for Z3 cost around 30$ at the time of attempting this repair.

If your screen is flooded by LOCA, and a new one costs more than you’re willing to pay without trying to fix the old one, then this is the guide for you. This screen for Z3 cost around 30$ at the time of attempting this repair.

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Step 2

• The first layer to remove is the rear mirror of the LCD. There is usually mild adhesive or very very thin double-sided tape holding it in place.
• To start, take your exacto knife and optionally place pieces of thin tape on either side of the blade to dull the edges a little bit, but leave the sharp edge unobstructed. This way you can effortlessly cut through the adhesive but don’t scratch the layers of the screen with the sides of your blade.
• Pay close attention to the cutting process of the adhesive, and move slowly, to avoid slashing the rear mirror layer, which is very thin.
• After peeling open the rear mirror film, you see the first splatters of LOCA. Wipe them off with alcohol and a lint-free cloth, and you can then assess the situation again: if there is more glue in between the next layers, you will have to continue.

The first layer to remove is the rear mirror of the LCD. There is usually mild adhesive or very very thin double-sided tape holding it in place.

To start, take your exacto knife and optionally place pieces of thin tape on either side of the blade to dull the edges a little bit, but leave the sharp edge unobstructed. This way you can effortlessly cut through the adhesive but don’t scratch the layers of the screen with the sides of your blade.

Pay close attention to the cutting process of the adhesive, and move slowly, to avoid slashing the rear mirror layer, which is very thin.

After peeling open the rear mirror film, you see the first splatters of LOCA. Wipe them off with alcohol and a lint-free cloth, and you can then assess the situation again: if there is more glue in between the next layers, you will have to continue.

Step 3

• As you can see, for me, there was LOCA in between pretty much every single layer. Just keep slashing the side adhesives open with the exacto knife (gently) and move the layers in a logical order to the side, keeping them as clean as you can. Avoid getting finger grease on them.

As you can see, for me, there was LOCA in between pretty much every single layer. Just keep slashing the side adhesives open with the exacto knife (gently) and move the layers in a logical order to the side, keeping them as clean as you can. Avoid getting finger grease on them.

Step 4

• As you remove the layers, mind the LCD flex cable, as it is very fragile, and your knife can slip through it very easily, rendering the whole screen totally worthless.

As you remove the layers, mind the LCD flex cable, as it is very fragile, and your knife can slip through it very easily, rendering the whole screen totally worthless.

Step 5

• This is one of the polarizing layers. In the picture circled in red you can see why using a playing card or a tape-covered blade might be a good idea. The scratches didn’t show really at all in the end, though.

This is one of the polarizing layers. In the picture circled in red you can see why using a playing card or a tape-covered blade might be a good idea. The scratches didn’t show really at all in the end, though.

Step 6

• This is the layer that ensures the even, planar spreading of the backlight around the LCD.
• The backlight is emitted from the strip of LED’s that all seem to have around 3volts voltage drop across each LED. In total the backlight LED strip requires around 16volts, supplied through a three-pin connector by a some sort of switching power source.
• Apparently, there are two separate ground rails and a common Vcc, each operating half of the LED strip. These are possibly connected in parallel.
• To see LOCA stains clearly, you need to be looking at the pieces from the correct angle (second picture).

This is the layer that ensures the even, planar spreading of the backlight around the LCD.

The backlight is emitted from the strip of LED’s that all seem to have around 3volts voltage drop across each LED. In total the backlight LED strip requires around 16volts, supplied through a three-pin connector by a some sort of switching power source.

Apparently, there are two separate ground rails and a common Vcc, each operating half of the LED strip. These are possibly connected in parallel.

To see LOCA stains clearly, you need to be looking at the pieces from the correct angle (second picture).

Step 7

              The backlight strip               

• Eventually you will end up with the string of LEDs that are the backlight at the top. They are only glued into place with mild adhesive and can be removed quite easily. Just avoid cutting into the backlight strip.
• If you do ruin the LED strip, you will at least be able to salvage some fairly bright but energy efficient SMD LEDs for future tinkering.
• In this picture you can also see how much dust there actually can be on the layers. Always blow a bit of pressured air at the parts when reassembling

Eventually you will end up with the string of LEDs that are the backlight at the top. They are only glued into place with mild adhesive and can be removed quite easily. Just avoid cutting into the backlight strip.

If you do ruin the LED strip, you will at least be able to salvage some fairly bright but energy efficient SMD LEDs for future tinkering.

In this picture you can also see how much dust there actually can be on the layers. Always blow a bit of pressured air at the parts when reassembling

Step 8

              Stripping off the backlight strip               

• Just slowly edge your exacto knife through under the backlight strip to remove it.
• Avoid cutting the backlight cable. If you do accidentally cut it, and know some basics about microsoldering, you could consider repairing it using this guide.
• Proceed to unplug the backlight to remove it. In some cases the backlight flex is soldered onto the LCD flex, but can be desoldered and later reattached with relative ease. Or you can just leave the backlight flex be, it might not need to be removed to successfully clean the remaining LCD layers.

Just slowly edge your exacto knife through under the backlight strip to remove it.

Avoid cutting the backlight cable. If you do accidentally cut it, and know some basics about microsoldering, you could consider repairing it using this guide.

Proceed to unplug the backlight to remove it. In some cases the backlight flex is soldered onto the LCD flex, but can be desoldered and later reattached with relative ease. Or you can just leave the backlight flex be, it might not need to be removed to successfully clean the remaining LCD layers.

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                    Antti Immonen                     

Member since: 01/06/2015

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Michał Wojtas - Feb 1, 2017

Reply

I have the same problem with my Z2. I’m wondering how possible it is that I will positively remove LOCA from theese layers? Is it 80% or about 10% :P And what can I use to clean glue? petroleum ether will be ok?

Michał Wojtas - Mar 13, 2017

Reply

Ok, I made it, and if you want to know - glue is very hard to be cleaned from theese layers - it stay in theese little scratches. However I replaced almost all layers from another broken LCD and despite fingerprints and some ashes, it is working, but with many brighter spots. Still better than loca glue, thanks mate!

trnilsson - Feb 29, 2020

Reply

How does LOCA glue get in between those layers in the first place? And how do you prevent LOCA glue from getting in there, if it hasn’t yet? I am planning to replace a touch-screen on a Z3 and the new touch-screen will be glued with LOCA, so that’s why I’m wondering.

Antti Immonen - Mar 1, 2020

LOCA flooding results from excess use of the glue in digitizer-only repairs, especially if you have the gluing process oriented so the the LCD is on the bottom. After a few screens you develop an understanding of how much glue you should use and the correct patterns to spread the glue, so that just enough glue is used to cover the entire LCD.

The glue flooding may also be alleviated using other methods. This guide here is for damage control, but you can experiment with dispensing machines and OCAs+bubble removal. I also successfully used thin transparent tape overhanging the LCD sides, with only about 0.5mm on top of the LCD itself. After partially dry, I would remove the tapes and have no spillage on the LCD. But once you learn to apply the correct amount of glue in the correct pattern and to press the Digitizer, no such tricks are needed.

I haven’t myself made these repairs in almost 5 years so my info may be outdated. But you will find out more by just experimenting and learning in the process. Good luck.