Huawei y7 2018 Screen replacement issue. Please help! - GSM-Forum

stratf01 · 12-12-2018, 00:28

So I had a y7 in for a screen repair which had a display before removal. After opening it up there was obviois water. I cleaned up the board and tried the new screen but no display at all and nothing showing with light on it. I tried rebooting etc but no joy. I assumed it was the board at fault.

Anyway I just got another one in and this time there's no water damage and exactly the same fault again. No display on new screen. Old screen won't show display anymore either.

I guess perhaps the new screen is faulty and old screen unable to now display?

Has anyone else had a similar experience with these?
Any solutions pls?

Thanks very much

Jenifferliu123 · 12-26-2018, 08:54

Ask someone to repair it

ksktechnics · 04-19-2019, 11:23

Hi, Stratf01.
I suppose if you have entered this post, it is because you have a Huawei Y7, I ask you a big favor to see if I can solve a problem with a Huawei Y7 2018.
This cell phone does not show me an image, after doing an ultrasonic cleaning.
Attached the only plans that are on the internet:
https://postimg.cc/ctTsy2wB
https://postimg.cc/4nRQWdP1
https://postimg.cc/1gzWDpHm
https://postimg.cc/V59Bp8HP
https://postimg.cc/gLdVmJ7F
Could you confirm that at the output of the Shottcky diode, from the image called "lcd2", there are 24 volts?
In some videos, I hear that the coils are never connected to ground, or that some backlight coils have some coil of ground, although it is not usual.
Can you tell me in this case, in the image called "lcd2", the coil marked with a red circle, could be connected to ground? Because I verified it in the Y7 that I am trying to repair, it is, although the Coil that is underneath it is not.
If this coil was defective, could it be the cause of the output of the PMI8940 not being on the 24 volts of the backlight? Because when I measured it, I only got 4.7 volts.
Is the PMI8940 defective or is it a problem with the coil?
I hope that you share your wisdom with all those who do not dedicate ourselves, with greater or lesser fortune, to the reparations and what can be given a little light in the resolution of my problem.
Regards, and thank you very much.

12-12-2018, 00:28	#1 (permalink)
stratf01 Crazy Poster Join Date: Nov 2015 Posts: 50 Member: 2487844 Status: Offline Thanks Meter: 6	Huawei y7 2018 Screen replacement issue. Please help! So I had a y7 in for a screen repair which had a display before removal. After opening it up there was obviois water. I cleaned up the board and tried the new screen but no display at all and nothing showing with light on it. I tried rebooting etc but no joy. I assumed it was the board at fault. Anyway I just got another one in and this time there's no water damage and exactly the same fault again. No display on new screen. Old screen won't show display anymore either. I guess perhaps the new screen is faulty and old screen unable to now display? Has anyone else had a similar experience with these? Any solutions pls? Thanks very much

12-26-2018, 08:54	#2 (permalink)
Jenifferliu123 Junior Member Join Date: Nov 2013 Posts: 7 Member: 2070709 Status: Offline Thanks Meter: 1	Ask someone to repair it

04-19-2019, 11:23	#3 (permalink)
ksktechnics Junior Member Join Date: Jul 2017 Posts: 28 Member: 2741509 Status: Offline Thanks Meter: 17	Hi, Stratf01. I suppose if you have entered this post, it is because you have a Huawei Y7, I ask you a big favor to see if I can solve a problem with a Huawei Y7 2018. This cell phone does not show me an image, after doing an ultrasonic cleaning. Attached the only plans that are on the internet: https://postimg.cc/ctTsy2wB https://postimg.cc/4nRQWdP1 https://postimg.cc/1gzWDpHm https://postimg.cc/V59Bp8HP https://postimg.cc/gLdVmJ7F Could you confirm that at the output of the Shottcky diode, from the image called "lcd2", there are 24 volts? In some videos, I hear that the coils are never connected to ground, or that some backlight coils have some coil of ground, although it is not usual. Can you tell me in this case, in the image called "lcd2", the coil marked with a red circle, could be connected to ground? Because I verified it in the Y7 that I am trying to repair, it is, although the Coil that is underneath it is not. If this coil was defective, could it be the cause of the output of the PMI8940 not being on the 24 volts of the backlight? Because when I measured it, I only got 4.7 volts. Is the PMI8940 defective or is it a problem with the coil? I hope that you share your wisdom with all those who do not dedicate ourselves, with greater or lesser fortune, to the reparations and what can be given a little light in the resolution of my problem. Regards, and thank you very much.