LCD Backlight is on but there's no video output - Xperia Z2 Q&A, Help & Troubleshooting

Hello!
My phone fell from a high place some weeks ago and the screen shattered. Touch was unresponsive, clicking everywehere, but LCD was fine, i could see everything on screen normally.
Ordered a new screen. Changed it, but when I turned it on, only backlight of the LCD was visible, but it was displaying nothing. I thought it was a defective screen (either way, it was, lots of stuck pixels), sent it back and bought another from the same seller. When I changed it and turned it on, again, no video output, lcd would light on but woundn't display nothing on screen. Googled a bit, found out it could be a defective fuse on the motherboard, and that soldering it again would solve. I know nothing about this kind of stuff, so I picked up a tweezers and apllied a little force on every fuse, because I thougth that way I could try to solve it. Well, it worked, kinda. I put the screen above that blue plastic glue only for testing, and it worked, I felt reliefed for seeing sony boot logo again. Figuring out it had worked, i took out the screen, took out the blue plastic, and glued the screen back on. For my surprise, it had the same problem as before, and it doesn't matter what I do now, it wont work anymore, only displays a black backlight with no video.
Could anyone help me out with this? Give me a hint of why it worked once but not anymore. Could it be there's really a defective fuse, or it was just a coincidence that it worked after it had force apllied? Also, the Screen flex is kinda loose, it keeps coming off all the time, and it's really hard to plug it to the LCD sometimes, is it supposed to be like that, or could it be the culprit? Also, touch is working normally, i can't see nothing on screen but i can click and feel it vibrating.
It's kind of a big text, but that's the way I could explain it. Sorry for the bad english, it's not my native language.
And thanks in advance if anyone can help!

Related

[Q] Streak 5 not displaying anything

So, being clumsy, I left my Streak in my hoodie pocket. Well, we can all see where this would end badly once I bent down to pick something up. I did, dropped my phone and cracked the screen.
I quickly went and bought a replacement glass + lcd display, and replaced the unit. But, upon turning the phone on, I noticed if I hit it a little too hard on one corner, It would restart, and the vibrator motor had ceased to work.
So I figured, hey, I'll just rebuild it again. So I took it apart. Looked through everything, took my time in putting it back together, because maybe everything wasn't fitting snug.
Now, When I turn it on, every thing is on, buttons light up, and the screen is lit up, but it is black. I never even get to the Dell logo. After about a minute the buttons dim, as if in idle. So i believe the phone still works, but maybe the connections on the MoBo is faulty? Any help would be nice, thanks.
check to see if the ribbons are snugged in place.
mofoahh said:
check to see if the ribbons are snugged in place.
Click to expand...
Click to collapse
I agree take it apart and chech your work. I had problens with my camera and flash. It was tge connector not being fully seated
Sent from my Dell Streak using XDA App
Well, I just took off the rear cover and reseated all 3 connections, pushed em in as smoothly and far as they would go. But, same thing. Black screen. But the LED is still working...
I'm having the very same problem. This is my second replacement screen and neither displays anything except black screen with backlight on, and the home + settings + back buttons remain lit. I can hear my phone starting up and receiving messages, but I cannot see anything. I've taken the phone apart and put back together five times between two replacement screens.
Does anyone know what ribbon cable might be at fault for this particular issue? The largest ribbon cable was shipped bent across the circuit board on both screens; there is a permanent creese in both ribbon cables, but I'm not certain this is causing the issue.
Any insight or assistance with this issue would be greatly appreciated!

[Q] Help Please With My Screen :( i9100

Hi,
I dropped my Galaxy S2 Yesterday (have no idea if this relates to it) But i plugged it into the charger this morning and everything was blue & some of the screen had turned black and some icons had burnt into the screen it looked like.
After taking it with me because it was still usable, Its not completely black except for maybe the faintest part of blue.
Im running Lite'ning rom, The newest one im pretty sure.
Just wondering if this is a virus? Or the screen is dead. I just cant see how it could suddenly die when it was flat and not turned on.
Phones not under warranty by the way. So maybe you could give me some options?
Thanks heaps guys
Probably the problem is hardware related due to the fall, but you could back all your data and try to do a factory reset to see if it fixes or not. If it doesn't fix maybe you should check your screen hardware.
Thanks for the reply,
I just reflashed Litening with Odin 1.85 and still nothing, I get the vibrations, touch lights, sound ect, But only occasionally a tiny little strip of blue along the top.
How would i check my screen hardware? Because i pulled apart my galaxy s after it died and accidently cracked the screen & Glass
How would i do a factory reset by the way? Since i cant see anything
I'd imagine it's dead. I'd take it to your local store and ask for an estimate on how much it would cost to fix it. If you can't see anything, then the screen is either broken or it got disconnected (or maybe some of the ribbons did at least).
Yeah, I just dont really wanna take the phone apart unless i know its likley to fix it.
When i first got it, I noticed it had black splotches on the screen in very dim light on a white background. Nd im guessing id have to almost buy a whole front screen assembly to replace the front screen D:.
Would i be better just to sell the phone how it is? Or repair it?

[Q] [HELP] Xperia Mini Pro Broken Screen

Hello! So my Xperia Mini pro has been broken, it doesn't show any image anymore, I think there is a problem with the screen but I want a confirmation or recommendation to find out what the problem is.
First the screen "touch" capability stopped working, and then two weeks after that, the back and option buttons stopped working too. And a week after that ,there was like a screen "flickering" (I tried to recreate the problem in the attached image) when I tried to either open or close the slider.
Finally the screen stopped working anymore. I tried to connect the phone to the PC but says that windows cannot recognize the hardware. And there's one more thing: I can turn on the phone, it vibrates, but the keyboard lights seems that are not working, they are permanently off.. and when I try to Increase the volume it doesn't sound either... There is only the black screen and a backlight.
Please Help me to find out what is the problem, I'm thinking to buy a screen replacement on eBay, but some people told me that is the "flex" cable. I'm not sure if there is a fix for my phone's problem.
Thanks!
Hey there.
Based on my experience, yes, your problem is most likey a flex ribbon issue. Your flex has been ripping apart lately, causing many of its wires to break. This can cause a lot of unpredictable problems, such as a misbeheaving notification LED, inactive ambient light sensor, or "dead" display/touch digitizer. Your problems have gotten worse over time, which is clearly a symptom of a broken flex.
You phone is no longer booting up to android because the kernel no longer detects a proper "response" from the display driver and halts the bootup. This is why you can feel the phone vibrating when pressing the power button, but nothing else happens. Your screen assembly is fine, I can assure you that, unless your glass is broken, of course.
Here's one hell of a good teardown guide: http://www.ifixit.com/Teardown/Sony+Ericsson+Xperia+Mini+Pro+SK17i+Teardown/7275
I used that very same guide when I repaired my own xmp. I regret messing with my screen assembly because I destroyed it and had to buy a new one, which is costly
Thank You so much for the advice ! Now I'll try to repair it, It doesn't seem too difficult. Thank You Again!!!

Changed digitizer, LCD doesn't work

Hey guys,
I am not sure if this is the right forum to ask, I am desperate and I need your help.
My navigation buttons started to push itself, so I disassembled my phone (gently of course)
I found out that the digitizer flat cable is torn like.. 3/4 of its width so that was probably the problem.
I ordered a new digitizer and it arrived yesterday, so I put everything together, started the phone and the LCD doesn't work.
When I start the phone it vibrates as usually, then the LCD screen turns on for couple of milliseconds so I can just barely see the HTC logo and then it turns black, the navigation buttons are lit and I've heard notifications after I let it run for 30 seconds.
What could be the problem? I checked multiple times if all the flat cables are plugged in correctly. It's weird that the LCD runs for couple of ms and then it turns black.
Thanks a lot for your answer,
Adam K.
How bright does the LCD get? It is possible the lighting element went bad.
It gets bright as usually, but just for half a second, then there's just black screen.

Touchscreen ghost touches(screen flickering)

Hey guys, recently I had my Z2 sent to a service shop because it wasn't turning on or charging. The guy at the shop said that it was the battery fault and he changed it, but he also told me that the screen was not working( flickering, ghost touches, unable to work on it). So he put my old battery on and when I went home the phone actually turned on and booted up, but still I had the screen problem. So whenever I touch the screen it doesn't respond and it touches by itself. Tried putting it on rice for 20 hours, dried with a hairdryer and assembled dissamssebled the screen jacks, still the problems wasn't fix. Do I really need to change the whole LCD or is this a problem that can be fixed?
Shawiee said:
Hey guys, recently I had my Z2 sent to a service shop because it wasn't turning on or charging. The guy at the shop said that it was the battery fault and he changed it, but he also told me that the screen was not working( flickering, ghost touches, unable to work on it). So he put my old battery on and when I went home the phone actually turned on and booted up, but still I had the screen problem. So whenever I touch the screen it doesn't respond and it touches by itself. Tried putting it on rice for 20 hours, dried with a hairdryer and assembled dissamssebled the screen jacks, still the problems wasn't fix. Do I really need to change the whole LCD or is this a problem that can be fixed?
Click to expand...
Click to collapse
Yes, you have to change the screen, or more precisely, the digitializer.
But since the LCD and the digitialier come in one-piece, you have to change it as a whole, but at a much lower price, as your screen can be sold again and recycle the good LCD panel.
iXaidyiu said:
Yes, you have to change the screen, or more precisely, the digitializer.
But since the LCD and the digitialier come in one-piece, you have to change it as a whole, but at a much lower price, as your screen can be sold again and recycle the good LCD panel.
Click to expand...
Click to collapse
So replacing the LCD would fix the problem right? That's great then because I found an LCD with a very low price (20$), completely new on ebay and I sucessfuly dissassembled the old LCD out of the phone. I'm gonna buy it as soon as possible. Thanks man.

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