Screen Problem - MTCB Android Head Units Q&A

A friend of mine has a problem with his screen, see pics, it very strange and its somehow related to the SoM not the screen - I ve swapped the SoM for the one in my unit and the problem is cured on his unit but mine has it, I swapped them back and mine is fine but his has this problem.
It was on 5.1.1. and I ve tried several versions of 5.1.1. and several versions of 4.4.4. but I always get the same problem.
Any suggestions ?

Have I found the cause I wonder ? In the attached pic you can see a splodge of solder on what I m going to guess is the video output controller or something.

typos1 said:
Have I found the cause I wonder ? In the attached pic you can see a splodge of solder on what I m going to guess is the video output controller or something.
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Click to collapse
Who would carelessly drip solder into the unit? if it were to drip somewhere vital it would have fried or fry your car wires, even worse catch on fire.

alukarulz said:
Who would carelessly drip solder into the unit? if it were to drip somewhere vital it would have fried or fry your car wires, even worse catch on fire.
Click to expand...
Click to collapse
Theres no solder anywhere else and I dont think it dripped past the lid and the DVD player leaving no trace, I think someone was working on it for some reason or maybe bad quality control at the factory.

Did removing the solder splash resolve the issue?

marchnz said:
Did removing the solder splash resolve the issue?
Click to expand...
Click to collapse
Not done it yet, gonna try later . . .

I am interested too I've got the exact same problem. Pumpkin send me a new screen even though I've got no warranty anymore and the problem disappeared. Sadly this new screen is without a flex cable for the touchscreen so commands were not possible.

Draiden said:
I am interested too I've got the exact same problem. Pumpkin send me a new screen even though I've got no warranty anymore and the problem disappeared. Sadly this new screen is without a flex cable for the touchscreen so commands were not possible.
Click to expand...
Click to collapse
Yes, but the problem on my friend's unit is not screen related.
Why cant you use the cable from your old screen ?

typos1 said:
Yes, but the problem on my friend's unit is not screen related.
Why cant you use the cable from your old screen ?
Click to expand...
Click to collapse
Okay but screen issues are exactly the same.
The new screen has only one flex cable it's working but touch commands are not recognised. And the old screen has two flex cables.
Edit: I don't know if the new screen suffers the same problem because I had it running for only one minute and the screen issues are randomly.

marchnz said:
Did removing the solder splash resolve the issue?
Click to expand...
Click to collapse
Yes, it did !!
Half an hour of holding a soldering iron to a piece of copper braid and rubbing them over the solder/components covered in solder sorted it !
I used an iron that isnt quite hot enough to melt the solder used on these devices and it melted the solder splash easily, suggesting it was household solder or solder left by someone after the unit left the factory.
Still it was an excruciating half an hour - I thought all that heat my damage the SoM and maybe possibly remove components.

Draiden said:
Okay but screen issues are exactly the same.
The new screen has only one flex cable it's working but touch commands are not recognised. And the old screen has two flex cables.
Edit: I don't know if the new screen suffers the same problem because I had it running for only one minute and the screen issues are randomly.
Click to expand...
Click to collapse
Your old screen assembly is the screen + touchpanel. That is why there are two flexcables. One for the screen, one for the touchpanel. Your new screen assembly is the screen only.
You would have to move the touchpanel from the old to the new screen. However, that could be very difficult when the touchpanel surface is fully glued to the screen surface. If you're lucky the touchpanel is only attached along the edges. Then you might be able to remove it and stick it to the new screen.
Easiest way is to contact Pumpkin and ask them to send you the full assembly, so screen + attached touchpanel.

Mau2012sim said:
Your old screen assembly is the screen + touchpanel. That is why there are two flexcables. One for the screen, one for the touchpanel. Your new screen assembly is the screen only.
You would have to move the touchpanel from the old to the new screen. However, that could be very difficult when the touchpanel surface is fully glued to the screen surface. If you're lucky the touchpanel is only attached along the edges. Then you might be able to remove it and stick it to the new screen.
Easiest way is to contact Pumpkin and ask them to send you the full assembly, so screen + attached touchpanel.
Click to expand...
Click to collapse
Pumpkin are just sellers, it may be better to contact the factory direct, mighty be cheaper too.

Yes thanks for your answers

Related

Faulty screen replacement?

Hi, I am kinda new to this forum and although I tried to find answer first, I didn't find any.
So today I tried to replace LCD screen on my broken Evo 4G (Sprint) and after many tries when I thought that screen doesnt fit I noticed that the metal casing inside isn't native part so I took it out too. Then the new screen fit very correctly. However, when I turned it on, colorful stripes and faulty pixels appeared and I think now, that I may broke the screen somewhere, although I dont see any cracks visually.
Can the experienced ones of you give me an advice if the screen is broken or what may be wrong? I attach the picture of screen when the phone is on.
Thank you in advance
andreasovo said:
Hi, I am kinda new to this forum and although I tried to find answer first, I didn't find any.
So today I tried to replace LCD screen on my broken Evo 4G (Sprint) and after many tries when I thought that screen doesnt fit I noticed that the metal casing inside isn't native part so I took it out too. Then the new screen fit very correctly. However, when I turned it on, colorful stripes and faulty pixels appeared and I think now, that I may broke the screen somewhere, although I dont see any cracks visually.
Can the experienced ones of you give me an advice if the screen is broken or what may be wrong? I attach the picture of screen when the phone is on.
Thank you in advance
Click to expand...
Click to collapse
did you connect it correctly? it looks like you might have damaged the connections, it happens if you didnt lift the little locks up and tried pulling it out
*sorry for the poor vocabulary, i replace screen all the times just not sure what the proper names for the parts are*
I understand what you mean. Does it mean for me that is useless to buy new screen as it would have the same issue or new one sould solve it? I mean if problem is the flex cable or pins on board?
Andreasovo
Sent from my GT-I9100 using xda app-developers app
andreasovo said:
I understand what you mean. Does it mean for me that is useless to buy new screen as it would have the same issue or new one sould solve it? I mean if problem is the flex cable or pins on board?
Andreasovo
Sent from my GT-I9100 using xda app-developers app
Click to expand...
Click to collapse
well if it is the flex cable it, then ordering another screen would solve the problem. but if it is the pins then ordering another one would be pointless. theres also a chance the lcd might be faulty. All the LCDs and digitizers that i buy i get them from Amazon :good: and so far all have worked perfectly.
Sounds like damaged pins on board from not releasing the pin cable latches before removing the cable from the board, in which case the phone is fubar and the only way to repair it is to replace the logic board or the device itself
We are legion, for we are many.
Sent from the DarkSide of the GalaXy with a MEK device
-EViL-KoNCEPTz- said:
Sounds like damaged pins on board from not releasing the pin cable latches before removing the cable from the board, in which case the phone is fubar and the only way to repair it is to replace the logic board or the device itself
We are legion, for we are many.
Sent from the DarkSide of the GalaXy with a MEK device
Click to expand...
Click to collapse
I dont see a way how I can recognize damaged pins as from my view it looks they are OK, but if they are easily damaged from inside, then it might be so. I will possibly try to get new screen cause I might use too much force when putting the last one into it.
Or any other guess?

[Q] What's broken in this situation?

Recently, I took time to replace the screen on my s3. (Just the Screen not the digitizer). After I attached the newer screen, I turned the phone on, theres sound, vibration, etc. But the display is not shown at all. Is it the digitizer that broke? Is it something else that broke?
P.S While I was removing the cracked screen, i accidentally turned on the phone when i was using the s3 phone kit (which was pretty useless imo). Could this have played a role?
Any help is appreciated.
Since the digitizer and lcd are separate parts, a broken digitizer should not cause a blank screen. I have replaced the digitizer on a couple of Samsung phones and the lcd always displayed an image but would not respond to any touches.
Is it possible the lcd is defective?
audit13 said:
Since the digitizer and lcd are separate parts, a broken digitizer should not cause a blank screen. I have replaced the digitizer on a couple of Samsung phones and the lcd always displayed an image but would not respond to any touches.
Is it possible the lcd is defective?
Click to expand...
Click to collapse
Sorry for the late response, I was just able to check the forums recently. The lcd was brand new. How would I be able to tell if it would be defective or not? I'll post pictures if necessary.
C0ax said:
Sorry for the late response, I was just able to check the forums recently. The lcd was brand new. How would I be able to tell if it would be defective or not? I'll post pictures if necessary.
Click to expand...
Click to collapse
If you can see an image on the screen, the LCD is not defective. If you can see an image but it doesn't respond to touches, the digitizer could be defective, the phone's motherboard is defective, there is a bad connection between the digitizer and motherboard, or all three.
audit13 said:
If you can see an image on the screen, the LCD is not defective. If you can see an image but it doesn't respond to touches, the digitizer could be defective, the phone's motherboard is defective, there is a bad connection between the digitizer and motherboard, or all three.
Click to expand...
Click to collapse
Does that mean, that I need to buy another screen and test it out? I can't really test out the other parts you were talking about because, the screen does not display any image at all.
Since you can't see an image, it could be the LCD. Is there a repair shop where you could askl them to test your LCD?
audit13 said:
Since you can't see an image, it could be the LCD. Is there a repair shop where you could askl them to test your LCD?
Click to expand...
Click to collapse
I think there is one nearby. Would I need to pay for it to be tested? I don't know if it's still worth getting my S3 fixed because my relative is going to give his note 3 to me since the S5 is supposed to be revealed soon.
I would double and triple check that all ribbon cables and connectors are 100% properly attached / connected before replacing anything else....
sewermike said:
I would double and triple check that all ribbon cables and connectors are 100% properly attached / connected before replacing anything else....
Click to expand...
Click to collapse
I only replaced the screen and didn't touch anything else. I used the tutorials on youtube for guidance, but sadly it didn't work the way i hoped.

[Q] Please help! Strange problem with my HOX

Yesterday i dropped my device from one feet. It turned off and i turned it on.
Now lower part of screen and capacitative buttons dont work. i will attach a image(non-working area outlined in red)
My warranty has expired so i cant exchange it for a new one. What should i do? Can i fix it by myself?
Please help me
Fycola123 said:
Yesterday i dropped my device from one feet. It turned off and i turned it on.
Now lower part of screen and capacitative buttons dont work. i will attach a image(non-working area outlined in red)
My warranty has expired so i cant exchange it for a new one. What should i do? Can i fix it by myself?
Please help me
Click to expand...
Click to collapse
Hi,
Only thing I can think of is that somehow it has damaged the cable from the touchscreen or the tiny wires that feed into the cable without damaging the screen. I came across a brand new screen I was replacing once for someone that had a similar problem where the bottom left hand corner wouldn't respond to touch unless there was firm pressure on the screen to create contact, and this was a brand new screen. It could also be that the touchscreen connector needs to be pushed back onto the board if it's come a bit loose.
If this is the problem, you can fix it by yourself although I'd have a good look around youtube, there are heaps of DIY videos of how to replace screens. If you do go down this path I recommend you replace the touchscreen/LCD/LCD frame in one go, as it's generally already pre- assembled the only thing here is that there are 3 brands of LCD's HTC used with the phone and they aren't all compatible, and you can only tell by pulling down your phone and looking at the LCD flex cable colours, and the other thing is that the screens that are available aren't always the same quality as the original. If this sounds to hard your best bet is to take it somewhere and diagnose the problem just in case it's something else

Black screen, only backlight works. Everything else is ok.

Hi
Sorry for my english, I'm hungarian, this is the best I can do.
So I bought a cheap (but not too cheap) SM-P905, but I can't get the screen to work properly.
The touch layer, the spen, the backlight works well, I managed to mirror the screen on my pc and everything else seems to be okay.
I got off the back cover, I tried to unplug and reattach every flex cable, even the battery. I tried to look everything under magnifying glass to see what could be the problem.
The lcd flex connector looks like this under my lens.
(Upload it in the next post, not working from the android app)
I tried to clean it with a needle, but it still looks like it is corroded or melted.
Is it possible that replacing this connector will get the screen back to normal? (I found flex connector replacement on the internet)
Or is it possible to repair it with some jumpers or something like this?
Is it melted because of some shorted circuit somewhere else, or because of a bad micro capacitor?
How and where can I locate and resolve this problem (s)? Maybe is it still the lcd that is simply dead and I can't bring it back to life?
I dont want to buy a screen, and a motherboard (neither only one of them )
Thank you for your help!
Okay the forum doesnt let me to insert links or photos, because I'm new here -.-
/s/53oab9sykbihn32/20151021_175009.jpg?dl=0 write dropbox dot com in front of link
https://www.dropbox.com/s/53oab9sykbihn32/20151021_175009.jpg?dl=0
In my opinion it died!!
I hoped for better opinions
I wanted to know how this thing can die?
It has to be caused by something.
Bad resistor/capacitor? Is it on the motherboard or on the lcd's circuitboard?? Or is it only the corroded flex connector??
I dont want to throw the whole tablet in the trash. Everything else is just operating fine.
If nobody can answer this, where should I write, where people can help with these very small components / resoldering / measuring what gone wrong here?
Alan-B said:
In my opinion it died!!
Click to expand...
Click to collapse
So today I measured the pins in worst condition. There are 2 pins that I tought can cause the problem and looks corroded. (Number 5 and 9 from the right) Both of them !are not used!. (There is a total of 3 pins that are not used on the connector/cable)
They are not lead through the flex cable, they have no function here.
So the problem comes from somewhere else, but I still don't know why they look like this.
Maybe I will try to seperate the screen from the body and look at it closer and its connectors/smaller circuit boards.
Sent from my SM-N9005 using XDA Free mobile app
Hmm, that pic does not make me think its a corrosion problem. At best, it can lead to a finicky connection, but there seems to be enough there for proper electrical contact. If this were a headphone jack, for example, I would say apply pressure near the cable to see if the headset works properly, and if it does, then I know its a cable problem. No idea if you can try to apply pressure to the cable and see if the LCD turns on.
If the screen mirrors on the TV successfully, then there are a bunch of Samsung Service Codes you can use to test the LCD. Unfortunately I do not know them for this model, but google should get you the service menu very easily. There is definitely a test in there for the LCD that should give you a better idea what to expect.
If the cable is pretty cheap, I would also just pick up one and try replacing. Nothing to lose! AND if you have access to another identical device, you can try to stick this LCD on that device to see if its the LCD thats the problem or the motherboard.
Lastly, I would want to know if the glass on that LCD has ever been replaced. If they did a glass only replacement, its possible they overheated the LCD ... OR used too much LOCA glue that shorted the connectors.
Many possibilities, so I wouldn't call it a day yet. First, look for the service menu, thats the best place to begin.
I will try the service codes.
Unfortunately I don't have more devices. The easiest way would be to test the identical parts on a working one, but I don't know anyone who would risk his/her tablet for this
The other thing I can do is to get another lcd-glass unit from ebay or from ifixit and try it. If the problem was the lcd, it should work, I'm happy, but if its black, I will have (maybe) 2 working lcd units for sale. Or I have to get a new motherboard (sounds expansive).
I don't think that they replaced the glass on this device, it looks very used and scratchy, so it was working before.
Thank you for taking your time for me and answering my dumb questions!!
Sent from my SM-N9005 using XDA Free mobile app
There are more good news than bad, so I'm very happy.
So 1-2 days ago I started to get off the screen to see if I can seperate the LCD from the receiver. Turned out its not that hard. The only hard thing is to get it off the body in one piece. Lots of heating with a hair drier, and a LOT OF PATIENCE. If you can get it off in one piece you are on your way.
Seperating the glass from the LCD is very easy, did it in 10 minutes, I don't think it needs heating...
So I did it, then I saw some water damage (white things) on the back side of the LCD. There is a small board here too, so I cleaned the white thing off with some alcohol.
Then I put the lcd back and voilá, Its WORKING!!!
The only problem is that I damaged the touch screen glass, so I need to order a new one, but its under 20$ so no problem.
Thank you all for your help, I hope that I finished here
Sent from my SM-N9005 using XDA Free mobile app
Good to know! Thank you for the update
Other solution is remove battery five minute and reconnect battery

Unit is working but screen is black - OFF

I have a KGL unit with RK3188 quad core CPU and 1024x600 screen.
I was working with custom ROM (made by Malaysk)
I didn't update anything recently.
Suddenly that morning, the screen is black.
I am able to hear the radio, and Bluetooth calls are being transferred through the unit, but the screen is totally black, zip, nada, nothing at all.
Any ideas what could get wrong?
I've had this happen before also. Do you see any boot logo at all?
Dave
I see nothing at all. Black all over the way.No logo
Sent from my A0001 using XDA-Developers mobile app
that is a hardware failure
contact yoru seller
unfortunately, the seller completely ignores my messages.
amir77a said:
unfortunately, the seller completely ignores my messages.
Click to expand...
Click to collapse
Did you tried to enter the recovery or it is shows black screen also?
If yes, maybe your display panel is wrong. If you seller ignore your messages, try to check your panel's contact to the board.
Check to see if you can get into recovery. If screen works, turn off lights when in rom. I had issue with auto brightness which was too low. Only way I could fix was to wipe and reinstall and turn off auto brightness.
Just updating... it was a hardware problem.
Flat cable problem + certain transistor.
Thanks for your comments.
How did you figure it out?
Dave
TT_Vert said:
How did you figure it out?
Dave
Click to expand...
Click to collapse
The buttons were OK, I was able to listen to radio, switch stations (via the wheel control), and even BT calls went through.
That made me guess that this is a hardware problem, and not software.
and no matter what you did you never got video ? Ive got this same problem but after a hard reset Ill get the video back sometimes.
TT_Vert said:
and no matter what you did you never got video ? Ive got this same problem but after a hard reset Ill get the video back sometimes.
Click to expand...
Click to collapse
Actually, I even didn't try to hard reset the unit.
Took it from my technician, and it was working, without any hard reset.
To be precise, I'm going to visit him again tomorrow, since the colors on the screen are a bit on the green side, and a bit smeared.
Not a disaster, but not as it should be.
I guess one of the flat cables inside the unit, is not in its place.
amir77a said:
Actually, I even didn't try to hard reset the unit.
Took it from my technician, and it was working, without any hard reset.
To be precise, I'm going to visit him again tomorrow, since the colors on the screen are a bit on the green side, and a bit smeared.
Not a disaster, but not as it should be.
I guess one of the flat cables inside the unit, is not in its place.
Click to expand...
Click to collapse
Did the technician just reseat the cables or was something actually replaced?
jakejm79 said:
Did the technician just reseat the cables or was something actually replaced?
Click to expand...
Click to collapse
At first replcaed something... the second visit, probably things were a bit loosen up...
amir77a said:
At first replcaed something... the second visit, probably things were a bit loosen up...
Click to expand...
Click to collapse
Any chance you could get details on what was replaced?
I had a similar issue - would lose screen output, it would go either black or white. Touch screen would still work, and radio/BT as well.
Then I'd disconnect the flat cable and reattach it, and it would work for a couple of days. Final solution (it seems) was to hold the flat cable with tape/hot glue!
Thank you, mine just went out again, it was fine for a month or so after reseating all the ribbon cables in the ZIF connectors, I'll do it again tomorrow and try securing them with some tape.
markinhosmrk said:
I had a similar issue - would lose screen output, it would go either black or white. Touch screen would still work, and radio/BT as well.
Then I'd disconnect the flat cable and reattach it, and it would work for a couple of days. Final solution (it seems) was to hold the flat cable with tape/hot glue!
Click to expand...
Click to collapse
did you reattach the flat cable with the radio on or off please help me because my head unit had became with black screen but the radio function normaly
Same symptoms here, any updates on what to look for? screen isn't even dim, touch works, sound works, it connects to my hotspot, but no visible screen, Witson PX5.
Which transistor ? I have a multimeter handy

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