Why white dots appear after replacing the polarizer?

Question

iPhone 5s

Repair information and guides for the Apple iPhone 5s that was announced on September 10, 2013. Model: A1533, A1453, A1457, A1528, A1530, A1518

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Roberto Silvestri @roby3493

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crwdns2931729:0crwdne2931729:0: N'w 23, 2016

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Why white dots appear after replacing the polarizer?

Hi everyone, I've a question for everyone that refurbish LCDs as a living.

When I refurbish iphone's LCDs I always remove the polarizer to speed things up, I clean very well the LCD to make sure there's no dust or streaks on it and then I apply a new polarizer film.

When I test the phone everything works great except for the fact that 9 times out of 10 I see very small white dots on the screen (you see 'em very well when you have a black image to see).

I read on the internet that small particles of dust "block" the light coming from the backlight and so you see a white dot (the same you'll see with no polarizer on the LCD but much smaller of course).

Now the question is: is there a way to avoid having this issue?

I know in China sell a dust free room to laminate polarizer and OCA films on the LCDs but I think paying more than 500USD for a simple metal bench with a fan spinning with a tent surrounding you is a ripoff.

Any suggestions?

Using compressed air did not help.

Thanks in advance

Roberto

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PhoneOpsPlus @phoneopsplus

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PhoneOpsPlus

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crwdns2931729:0crwdne2931729:0: N'w 23, 2016

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Refurbishing lcds must always be done in a 'clean room' what I mean by this is a room built to a specific requirement that doesn't contain dust, microfibres etc.

These small dust free rooms are a good start and definitely helps compared to doing it in a normal room, doesn't matter how much you clean, there will always be dust and fibres in the air unless you have a clean room or portable clean room.

Till you do this, you won't be able to refurbish without dust under your screens. :-)

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Yeah I see but the fact is I think paying 500 bucks for these kind of rooms is a ripoff.. Maybe you could build one diy...

crwdns2934271:0N'w 23, 2016crwdnd2934271:0 Roberto Silvestri crwdne2934271:0

Of course you could build a DIY one, and there's plenty of information and videos on the internet on how to build one! :-)

crwdns2934271:0N'w 24, 2016crwdnd2934271:0 PhoneOpsPlus crwdne2934271:0

I did some research on this and you will probably spend close to 500$ doing one yourself plus all the time designing and building. The filter is the most expensive component and you want to get a good one. Blowers are not cheap either, even if you find one used it'll likely be very noisy.

So yeah, you could build something perfectly suited to your needs or buy one but neither option is "cheap".

You also have to consider why you need this. If you plan on refurbishing screens as part of your business, then 500$ is not much compared to what you will earn or save. I did not hesitate to spend several thousand dollars on my micro-soldering setup and my ultrasonic cleaner. I need those tools to be successful.

crwdns2934271:0N'w 24, 2016crwdnd2934271:0 Minho crwdne2934271:0

As usual, I'm with Minho, $500 isn't much at all. Sounds like half a days work. You'll make that back in no time. If you skimp on quality parts and tools, you'll like yield less than quality products and services

crwdns2934271:0N'w 24, 2016crwdnd2934271:0 iMedic crwdne2934271:0

You could make $500 back in less than 2 - 3 hours especially if you're refurbishing and repairing.

At the end of the day, if you skimp out on essential things, you're going to end up with rubbish refurbished screens that you can't use or can't sell, and no one will want your service.

crwdns2934271:0N'w 27, 2016crwdnd2934271:0 PhoneOpsPlus crwdne2934271:0

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Yeah I see but the fact is I think paying 500 bucks for these kind of rooms is a ripoff.. Maybe you could build one diy... — Roberto Silvestri
Of course you could build a DIY one, and there's plenty of information and videos on the internet on how to build one! :-) — PhoneOpsPlus
I did some research on this and you will probably spend close to 500$ doing one yourself plus all the time designing and building. The filter is the most expensive component and you want to get a good one. Blowers are not cheap either, even if you find one used it'll likely be very noisy.

So yeah, you could build something perfectly suited to your needs or buy one but neither option is "cheap".

You also have to consider why you need this. If you plan on refurbishing screens as part of your business, then 500$ is not much compared to what you will earn or save. I did not hesitate to spend several thousand dollars on my micro-soldering setup and my ultrasonic cleaner. I need those tools to be successful. — Minho
As usual, I'm with Minho, $500 isn't much at all. Sounds like half a days work. You'll make that back in no time. If you skimp on quality parts and tools, you'll like yield less than quality products and services — iMedic
You could make $500 back in less than 2 - 3 hours especially if you're refurbishing and repairing.

At the end of the day, if you skimp out on essential things, you're going to end up with rubbish refurbished screens that you can't use or can't sell, and no one will want your service. — PhoneOpsPlus

iPhone 5s

Why white dots appear after replacing the polarizer?

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