HUAWEI y7 prime trt-l21a screen light solution - GSM-Forum

habibtarkegn · 11-17-2018, 16:23

HUAWEI Y7 PRIME TRT-L21A screen light not working

THANKYOU
Show me light ic pleas

habibtarkegn · 11-21-2018, 14:32

Any help i cant find the display ic

ksktechnics · 04-10-2019, 17:07

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.

11-17-2018, 16:23	#1 (permalink)
habibtarkegn Crazy Poster Join Date: Mar 2013 Location: ETHIOPIAN (wollo, mersa) Posts: 56 Member: 1908006 Status: Offline Thanks Meter: 12	HUAWEI y7 prime trt-l21a screen light solution HUAWEI Y7 PRIME TRT-L21A screen light not working THANKYOU Show me light ic pleas

11-21-2018, 14:32	#2 (permalink)
habibtarkegn Crazy Poster Join Date: Mar 2013 Location: ETHIOPIAN (wollo, mersa) Posts: 56 Member: 1908006 Status: Offline Thanks Meter: 12	Any help i cant find the display ic

04-10-2019, 17:07	#3 (permalink)
ksktechnics Junior Member Join Date: Jul 2017 Posts: 28 Member: 2741509 Status: Offline Thanks Meter: 17	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.