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2016年9月16日に発売。モデル番号は1660, 1778で GSM かCDMA があり。/ 32、128、 256 GB / 色はローズゴールド、ゴールド、シルバー、ブラック、ジェットブラック

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Where do I get this element from? (No backlight - motherboard issue)

Hi, I f*cked up.

I bought a supposedly dead IPhone 7, after some investigation i found out that it works just fine, but there’s no backlight. So of course like an idiot I bought a new screen without checking if any of the screen connectors are shorted. After installing the new screen and feeling like a big dum dum for a few minutes I found out that this connector is shorted

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and after checking where could lie the problem i found this component

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on the other side of the board. Now I don’t have a clue where i could find a component matching this one and even if I had the access to a similar one I have no clue what to search for, is it a resistor or a capacitor or a chip of some sort i have no idea (don’t flood me with some technical terms I barely even started to learn all of it). To anyone offering assistance I would be very grateful.

Edit:

I think I found what it’s called

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Update (11/19/2020)

Edit v2:

So I think I found the issue.

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This little guy FL3903 is shorted (both sides show an open line to TP0410 while only one side has to have an open line there, I think …). I think it can be caused by a bad U3701 chip or a bad FL3903 chip. I don’t know how to check which one it is but I’m betting on the U3701 chip because there’s a lot of tutorials on the internet for how to replace them.

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You have just started learning so before you go any further do some research and let us know why the component you have circled cannot have a path to ground and therefore could not be the problem unless pin 5 on the connector had an open line.

If you don’t want to learn and just want a please bro solution let us know but there is no fun in that and you will not learn anything. Plus that line has nothing to do with backlight.

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Thank you for the hints, I'll be back with some research <3

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@imicrosoldering I updated the post, could you please check if I'm on the right path?

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@madbox What I was trying to get you to learn was why FL3908 and the recent one you mentioned FL3903 cannot become shorted. The pads that they sit on do not go to ground. These components act like a fuse and protect the circuit. Do not start removing IC’s until you know they are faulty as it will only add variables to the repair.

You need to start from scratch and determine if you have a backlight problem or an image problem. You can do this in a number of ways, shining a torch on the screen is one way to check image or you could diode the backlight circuit at the connector.

Post diode readings of pins 35, 37 and 39 of the LCD connector. Remember red probe on ground.

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@imicrosoldering Ohhhh, I get it now. I know that it's the backlight problem because I first checked on the both screens, and on both the display is visible only by using a flashlight.

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@madbox Now you need to diode those connector pins and find out what line on the backlight circuit is faulty. You will be looking for an open line or shorted line. Pins 35, 37 and 49.

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This component is not related to backlight section

It is PN5.7 line which is aroung OL in diode mode and it generate by chestnut ic u r getting ur display image right if yes no issue of this line.

Check anode line on display connector buddy.

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Mateusz さん、ありがとうございました!
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