Unit is working but screen is black - OFF

[amir77a]

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?

 

[TT_Vert]

I've had this happen before also. Do you see any boot logo at all?

Dave

 

[amir77a]

I see nothing at all. Black all over the way.No logo

Sent from my A0001 using XDA-Developers mobile app

 

[doctorman]

that is a hardware failure
contact yoru seller

 

[amir77a]

unfortunately, the seller completely ignores my messages.

 

[neosnd]

unfortunately, the seller completely ignores my messages.

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.

 

[miffymiffy]

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.

 

[amir77a]

Just updating... it was a hardware problem.

Flat cable problem + certain transistor.

Thanks for your comments.

 

[TT_Vert]

How did you figure it out?

Dave

 

[amir77a]

How did you figure it out?

Dave

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.

 

[TT_Vert]

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.

 

[amir77a]

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.

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.

 

[jakejm79]

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.

Did the technician just reseat the cables or was something actually replaced?

 

[amir77a]

Did the technician just reseat the cables or was something actually replaced?

At first replcaed something... the second visit, probably things were a bit loosen up...

 

[jakejm79]

At first replcaed something... the second visit, probably things were a bit loosen up...

Any chance you could get details on what was replaced?

 

[markinhosmrk]

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!

 

[jakejm79]

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.