iPhone 6S No backlight

[abukuru]

If the two backlight filter good ,,,,always try and replace


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[BitRepairs]

my fix for this is to replace the whole backlight circuit, the ic always seems to **** with water damage, whenever i replace bits I always get a warranty return a few weeks later with the ic failing.

just replace the 2 coils, 2 diodes, the big capacitor and the ic.

Not easy because of all the underfill but this solution works every time for me.

[HDccam]

Your backlight coil L4020 is connected to VCC Main (Battery power). What is more important is to check if the coil pad of L4020 is still connected to the Anode side of diode D4020. This trace can be burned or eaten away. Jumper this connecton if damaged and put the coil back.

[MA7MOD_GSM]

pls check
ic U4020
coil L4020
coil L4021
diode D4020
diode D4021

[joeshannallie]

So if I jump the 2 filters as mentioned above, It should have backlight? There is no continuity(beep) with either one of them.

[joeshannallie]

Someone please reply soon.

[ninos22]

Originally Posted by iphonerepair12

hi

i have an iphone 6s (water damage, no signs of corrosion, but indicator is red) with a backlight problem.

I checked:
Fl4211; fl4212; fl4213, all ok
diode d4020 replaced (with iphone 5 one, but seems to be similar?)

without screen i measure about 3.5v on fl4211 and at one side of the diode (towards u4020)

i am not getting any voltage at fl4212, is u4020 defective? Or is there an other problem?

[b]during the measurements, no screen was attached.

Originally Posted by iphonerepair12

someone please reply soon.

Υou ask like we are obliged to answer - download schematics and read circuits and ways

first do you have image with out backlight or you have no image / no backlight?

if you have image and all filters ok,

test d4020 & d4021 first, and if bad replace with same (ip5 its not same of course)

if u4020 its bad probably will heated or some parts shorted to ground

for measurements you must have screen on board

[iphonerepair12]

Originally Posted by ninos22

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Υou ask like we are obliged to answer - download schematics and read circuits and ways

first do you have image with out backlight or you have no image / no backlight?

if you have image and all filters ok,

test d4020 & d4021 first, and if bad replace with same (ip5 its not same of course)

if u4020 its bad probably will heated or some parts shorted to ground

for measurements you must have screen on board

To be correct, I didn't posted the request for a quick answer...

Read the thread, and you will see that this board is death at the moment.

[joeshannallie]

Well, all I asked was if the 2 filters were crossed jumped or bridged or whatever you want to call it should I have a backlight. And yes you can see the images very faintly or with a flashlight. And also I do not know how to read the schematics like some on here do!

[ninos22]

Originally Posted by iphonerepair12

To be correct, I didn't posted the request for a quick answer...

Read the thread, and you will see that this board is death at the moment.

Sorry i did not find any post that says the board is dead.

So now what exactly is the problem?