Phone possibly damaged during repair. Screen shows pixel noise. - One (M7) Q&A, Help & Troubleshooting

Hello,
So I broke my screen on my HTC One and decided to repair, having done so before on previous phones I didn't think it would be a problem. Unfortunately upon installing the new screen all I got was a coloured and white pixel noise. Thinking it was a faulty screen I returned it to the supplier and sent off for a new one from a different seller. The new one has exactly the same issue however so now I think I have to conclude it is some sort of hardware issue, possibly caused by static during repair or something along those lines.
The bugger is that there were no issues with the repair itself, it was taken apart carefully and none of the cables damaged, wiggling or otherwise removing and replacing the ribbon cables that are responsible for the LCD has no effect on the noise pattern at all, it remains constant.
I can tell the ROM is running beneath the surface as it has the feature to turn on the flashlight with a long hold power press, and this still works. So the issue is purely with the processing of the image sent to the LCD.
I am unable to test the original LCD as the original cracks cause it to get too badly damaged to work during the original repair.
So I'm basically wondering if there is anything I can do to try and fix this, is there a part I can replace that deals with the LCD image or anything like that? I have a distinct feeling the phone is buggered, but it would be foolish not to ask the community here before sending it to the grave.

I have just discovered a damaged part on the circuit board just behind where the ribbon cable attaches to the mainboard. It is one of the very tiny little black squares, there is a row of 5 and one had a corner that looked damaged and came away when lightly scraped with a tool.
I think this must be the source of the problem, and I would guess means a new mainboard.

Related

Busted screen replaced, still not working

My dumb butt child was sucking on my phone a couple weeks ago and caused the LCD to short out or something. The phone still worked and if I used a bright light I could shine it onto the screen and barely make out what was on the screen. It was booting properly and I assume that if I could make out the menu options the phone would still function. I assumed that she shorted out the LCD so I ordered, received and replaced the LCD tonight. Apparently this was not the problem, sucks to be me. I do think there was a problem with the touch screen portion already which is now working properly again but still I can still not see the screen for crap. It's like the brightness setting is on 1 or something. If I use a flashlight I can make out the screen, use the stylus and operate the phone. When I was replacing the LCD I noticed that the two circuit boards to the north and south of the LCD seemed to have a bit of corrosion on some of the tiny chips. I used an alcohol swab to clean the area off but that didn't make a difference. I am utterly convinced that the motherboard is fine since it seems to be well protected in the case and not easily accessible to moisture. I see no signs of corrosion on the motherboard like I do the two circuit boards around the LCD area. I noticed that there are only two contacts on the LCD one of which is a cable that plugs into the south circuit board just underneath the front panel key pad. Just to the right of that cable connection is where I saw signs of corrosion so I wonder if that board is the problem.
The computer tech in me says that I could be swapping parts all night before I get this right. Since the LCD plugs into that board, that could be the problem, there is a ribbon cable that wraps around the back of the LCD which also seems to make contact with the LCD which could also be the problem, that ribbon cable plugs into the north circuit board, so that might be a problem and finally, the ribbon cable plugs into the main board so that too might end up being a problem.
Can anyone take a guess as to why I might be seeing such low contrast/brightness from the LCD? I have already adjusted the brightness setting in the menus. I think it was called the backlight setting, but I moved them to the far right with no change. Again, this is a near pitch black screen that is only visible when I shine a light onto the screen.
i haven't taken my tilt apart but as a computer tech repairing broken laptops etc i know your problem.
as for laptops, there is a little inverter card that powers the backlight. its connected to the display unit by 2 cables (same as with my digital camera, rip ) and this boards are really weak / vulnerable to moisture...
so most likely this board is damaged...
That sort of explains what I think is going on too. Take a look at this cable (apparently it's clickable and will grow slightly in size to give more detail):
Let me explain the cable. This fits directly behind the LCD. The LCD comes with one flat ribbon cable and it plugs into a port on the right side of this picture. On that right circuit board if you notice the top left portion of the board there is thin black slot which is where the LCD plugs into if I recall correctly. There is another cable that plugs in just to the right of that jack from where I forget actually, lol. Once that cable is flipped over the bottom keypad on the phone sits right on top of that board. In fact on the other side you can even see the contacts for the outside buttons. The buttons in question would be like the green phone and red phone, the "e" shortcut and pretty much all the silver external shortcut buttons. Getting back to the cable, you will notice that in the middle of the cable there is a rather wide connection and that is the one that plugs onto the motherboard.
When I was replacing the LCD I spotted two sources of corrosion on both boards. The more plausible culprit was about 1/8 of an inch away from where the LCD plugs into the right circuit board.
I sent HTC an email seeing if they would help to which they told me to send it in. I have no intentions of doing that. I already know how to disassemble and reassemble the phone at this point and I already have 35 dollars invested into a new LCD. I am not about to spend 250 bucks to have HTC take 3 weeks to replace that cable. After some searching last night though, I have no idea where to get the cable. It seems that all the normal parts places on the web want 90 bucks for this cable, but at the same time they want 120 for the LCD. Obviously prices have dropped some because I was able to get the LCD new from ebay for 35. I just need help finding a place that will sell me that cable at a reasonable price.
Now that you have looked at the cable and that board, do you think it's possible that the right board could be the back light inverter that you were mentioning? If that's truly the correct board then it would make since that there is something wrong with it since I saw signs of possible damage and the LCD does work, just not strong enough to be seen with the naked eye. Since these things tend to work much like laptops do, I am leaning towards the possibility that you totally know what your talking about and that it would make since that this is the faulty part.
One other thought, the backlight is the piece that increases the brightness of the LCD right and not just some sort of overhead flashlight or something, correct? The term backlight almost implies a different part but I am pretty sure it's the term used to describe the brightness of the LCD in this case. I just wanted to make sure we were on the same page here.
Any additional thoughts?
Thanks
okay, to be clear about this. i am not 100% sure, if the backlight on the kaiser works the same way as the one on my IBM Thinkpad T41.
tl;dr; i don't know if the kaiser actually has an inverter board.
as for the cable: if you found a bit corrosion on both boards, i'm pretty sure that the reason why your backlight doesn't work.
about the last part: yeah, with "backlight" i mean the unit sits behind digitizer and LCD and increases the brightness of the lcd so you are able to read everything on the screen. i don't mean an overhead flashlight
btw, i just found this one
http://www.cellulardr.com/50H10051-41M-XC.htm
selling the cable / boards or about 90$
<edit>
disregard that... i noticed that the boards allways come with that cable assembly.... and cost about 90$ everywhere... will keep an eye on that.
</edit>
I'm going through the same thing. Did you ever replace that piece? Please let me know because it sucks to not use this phone.

HD2 Repair

Hey guys,
The USB port of my HD2 broke off and I was forced to replace the motherboard. When I assembled the HD2 again, I could immediately see that there was something wrong with my screen. The screen couldn't display full color (only bright red/orange/white/dark green/cyan accents). Also, the 'hang-up button isn't responding anymore after I replaced the motherboard (and flexcable).
What happened? Is there something wrong with the lcd display or did something go wrong when I (dis)assembled the phone? I took the motherboard and the flexcable from another HD2 that had a broken display.
Thanks in advance.
bilaba70 said:
Hey guys,
The USB port of my HD2 broke off and I was forced to replace the motherboard. When I assembled the HD2 again, I could immediately see that there was something wrong with my screen. The screen couldn't display full color (only bright red/orange/white/dark green/cyan accents). Also, the 'hang-up button isn't responding anymore after I replaced the motherboard (and flexcable).
What happened? Is there something wrong with the lcd display or did something go wrong when I (dis)assembled the phone? I took the motherboard and the flexcable from another HD2 that had a broken display.
Thanks in advance.
Click to expand...
Click to collapse
So you completely voided your warranty through HTC and tried to fix the device yourself, then screwed it up. I'd still say send it to HTC and ask for a repair. I don't know if they'll do it or not, unless you used official parts. I know they do out-of-warranty repairs, but they'll charge you.....
Yep you screwed up the repair, those ribbon cables need a delicate touch & any handfisted moment ends up with what you have got now ...
Another careful strip & inspection of all ribbon connectors is needed ...
I bought it as a second-hand phone. The guy didn't give me a reseat and the HD2 was flashed a WP7 ROM.
For the button problem, how are you turning your phone on without that button? do you hear/feel it click when you press it? If not its just misaligned.the buttons are on a flex ribbon cable with two holes on each side. it fits on the plastic middle frame of the phone which has two small spikes coming out of it... it has to be perfectly placed for your buttons to actually click..
if the flex ribbon is broken however you can buy one off ebay for arround 10$ any will do, mine is not original works fine..
for the screen you could have messed up the lcd, did you separate from the glass-digitizer? if you did you probably screwed it up.. its not a easy thing to do.. also was not necessary for your repairs
the connection to the motherboard might not be all the in and clipped which might cause your problem... (being that two of the little pins provide voltage and ground while all the others provide data information if one of those pins is not in all the way a piece of data might not be displaying for example a color. Never seen that happen its theoretically possible thou)
well I have only opened my phone 3 times and dont claim to be a expert.. but this is my take on it... Good luck!
@pablow Thanks for the detailed response.
The HD2 is only turned on, after I place the battery. Otherwhise it won't start.
I hear a click on the (broken) 'off' button, everytime I press it. I also noticed that the inside of not all of the 'spikes' are empty. I can see a bit of the flexcable in the spike of the broken 'off' button. The spike of the (working) 'call' button is empty.
I think that the flexcable hasn't been connected securely to the motherboard. I'll try connecting everything again tonight.
not that it makes much difference but HTC wouldn't of fixed it through warranty because of usb damage anyway
I thought so, thanks for the heads-up anyways.
[Solved] Display is fixed
Update:
I disassembled the HD2 and reconnected everything (from coax to flexcable). Fortunately it worked! The display is how it should be.
I have another problem now. All of the buttons don't work now, exept for the dial button. Do these buttons break so fast? It's annoying as fuark, because I have to disassemble it another time in the future to fix the buttons.
I also couldn't re-attach the volume control tab when assembling the HD2.

[Q] What happened to my screen?

Hey guys,
I recently bought a Samsung Galaxy S i9000 and the Amoled screen has some serious issues with colours. It appears that the red part of the screen is messed up and cannot display any true white anymore. This happens in download mode, recovery, even in a custom ROM. It's definitely hardware. This video should explain it:
Yes, this phone is pretty much screwed, and the home key is no longer functional at all now. However, I've fixed the rotation sensor issue, and I've thought about repurposing it at a remote for my XBMC media center
Firstly, has anyone seen this issue with the screen before, and secondly, has anyone fixed it? It may be an internal connector which is loose. Suggestions would be good, otherwise I'll just have to put up with the annoying blue tint.
Cheers!
Anyone? Is this more likely to be the panel itself or a cable? Wondering if it's fixable or maybe the connector could be corroded...
Take it apart, remove the mainboard, and clean the board with Isoprophyl-alcohol. Its a 70% alcohol, here in germany you can buy it in a pharmacy. I use a paintbrush to get electronics clean safly.
And also clean the connectors that go from the phone to the board with the alcohol. I suspect there is some kind of water damage in your phone. Samsungs are realy *****y when it comes to water. Even sweat sometimes is enough to cause problems.
To take it apart you only need to remove the 7 screws under the back cover, pull of the back and the board is just held in place by the connectors.
Try youtube if you get stuck. There are some Galaxy S disassembly videos.

Huawei p9 black screen

Sorry if this is the wrong place to post or it's been covered already. I have a p9 stock that I changed the screen on after dropping it. Everything was fine until the new screen started to fail, it was a cheap eBay screen and the glass started peeling away. I fitted a new one and when I switched it on the backlight comes on but no image, backlight then flashes 5 times and then stays on. The phone does the one vibration like it's starting up but after that does nothing. I tried the reset procedures but doesn't help. It wasn't on USB debug so I can't connect with my pc. I first thought the screen was faulty so had the vendor replace it but still have the same problem. Could it be the main board has been damaged or the flex cable?
Sounds like a batch of bad screens. I would stay away from eBay when it comes to Huawei P9 screens, too many issues with them. Had ones that were refurbished or glass separating from the screen frame.
Buying it without the frame and applying the adhesive yourself seems to work better for me. Anyway hopefully you didn't kill the backlight circuit on your phone.
benjamen50 said:
Sounds like a batch of bad screens. I would stay away from eBay when it comes to Huawei P9 screens, too many issues with them. Had ones that were refurbished or glass separating from the screen frame.
Buying it without the frame and applying the adhesive yourself seems to work better for me. Anyway hopefully you didn't kill the backlight circuit on your phone.
Click to expand...
Click to collapse
Backlight seems to be fine. You could be right, there's a faint blue tinge in one area.
Hey, did you ever solve this? I have the very same problem

Failed display + frame repair

Hi guys
I just changed my mi 9 lite display incl frame the other day. Old one was cracked and dead.
Followed a legit online instruction on how to do the procedure and it went quite well. At least that's what I thought...
It appears that I might have caused damage or done something to the mainboard. If I put everything were it's suppose to be and fit the mainboard with the screws the phone gets stuck in a bootloop as soon as it starts. It starts showing the Mi logo and then it turns black and starts over and over until a disconnect the connector from the battery.
However if I lift the mainboard from the frame just a few millimeters the phone is able to start and the screen works.
I figure I have damage some part and I'm guessing it won't be a fixable issue unless I change the main board. I just want to reach out to see if anyone has run into something similar or happens to know if I've done a simple and fixable error.
Here's a video of the bootloop:
https://imgur.com/a/JOcap23
All type of help is appreciated!
The mobo was likely damaged by the impact. BGA chipsets are particularly sensitive to board flexing and no way to examine the hidden solder joints for damage. Use optical magnification and carefully examine all visible solder jionts for fractures. Double check all connectors for damaged pins.
The mobo is suspectable to ESD damage as well when out of circuit. ESD protocols should be observed. I don't think this is the issue here though but keep it in mind. Static electricity can kill unharden inputs... or cause failures days, weeks even years latter. Insulation at semiconductor junctions is only microns thick and their over voltage tolerance is very low.

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