lcd problem ( white screen)

Hello.
my mini2440 with 3.5 inch screen have white screen but i can see windows
screen at some angle.i think my lcd brightness have problem and screen
appears as white.
please help me .

best regard

Same problem here. When playing with the "backlight" app included in qtopia
it sometimes gets back to normal, but it's very annoying.

Mine is doing it as well all the time I can just see the screen on a very
sharp angle I have tried everything and this compnay will not help at all I
have even asked for a refund,, I guess I will just keep posting everywhere
that this thing does not work its to bad to becuase it looks like a very
nice system

I had the same problem and got my board replaced.

Nikita I can only contact the company via email ,, where did you get yours?
I have sent 4 emails pleading with them for help I am really pissed ,, the
thing is I think this system is really nice if it will work cusotmer
service however is ridiculous
I would have to warn anyone not to buy this

I bought mine here:
http://cgi.ebay.com/mini2440-S3C2440-ARM9-Board-3-5-TFT-LCD-Touch-Screen...

Hi Nikita,

Who bares for the postal chargesfor the replacement in this case?
I also have a similar problem myself..

Hi,

It's a matter of agreement between you and the seller, I think. In my case,
the seller returned all postal costs.

Hello everybody,
seems I have a similar problem. I found no -5.5V suppli on my T35 TFT
board, chip U6 (mc34063) is hot and seems not works. May be just replace
this chip, I will try to do this today or tomorow.

Hello again, seems problem with TFT is solved. I have replaced U6 chip and
L3 inductor.

Hi everybody. I have the same problem a couple of days ago. My MINI2440's
power supply fais and I used a Fonera's one, with an output of 7,5V. I
thought that the LCD control board would have an internal regulator but
later I noticed that's not true. The 5 volts from the main board (in this
case 7.5V) comes into the LCD AVDD pin directly and in the datasheet I've
seen the max value for this input is around 6V. All the board runs OK, and
I can see the image if I put it in some angle. the "test points" of the LCD
board that marks 10V and -5.5V are OK, but the 20V test point of my board
only have 6.36V. I think the problem is the LCD (ref. TD035STED4) and I'm
going to buy some new one, but first I would like if anyone can tellme it's
opinion. Can be the LCD board or this is a LCD module fail?

Thanks in advance and sorry for my bad english.

Hi javieralso! Do you try to disconnect LCD flat cable and check 20V test
point again? If voltage in range, then LCD is damaged, I think.

best regards,
Sergio

Hi Serg_io (this name sounds like a spanish speak name and I'm spanish....)

I tested this 20V whitout the LCD connected and it's about 6,33V. The 10V
test point is about 8,55V.

The max value for AVDD (Analogic supply for the LCD) is 6V as I've read
into the datasheet and I connected it to 7,5V.  

I think it's time for a pray for my LCD soul... R.I.P. :-(

The problem is that I don't know if the LCD board is damaged too (I think
it's not damaged, but I don't know)

Hi javieralso! No, I'm from Ukraine :). About your LCD: by my oppinion you
have damaged LCD board, because you are see some image on the display and
low voltage can produce low contrast. First of all you need to restore 20V
without LCD connected and then check all together.

Hi Serg_io. I'll try to restore the 20V as you said when I get some free
time. 

I'll tell you my results.

Thanks for your suggest!! :-D

javieralso, did you managed to fix your LCD contrast?

i saw many people with the same problem, but nobody managed to fix it....

Best Regards

Guys, i changed the LCD itself and everything worked fine.... The LCD
Controller Board had no problem at all.... Hope this help someone...

Best Regards!!

Hi everybody. 

After a year since my LCD problem I changed U4 (TL431(A)CD), U5 and U6
(MC34063AD), and finally U8 (TL047CID), but my problem persist (the screen
is all white).

I checked the voltages in the tests points and all are OK but the 20V that
still have about 6.36V, so I decided to change the LCD itself (TD035STED4)
without solve my problem.

When I start the board, the screen flashes and is all dark. Later when the
linux kernel boots, the screen turns all white and I can see any image on
it.

Looking at the LCD module' schematic I've noticed that U9 is a
microcontroller with some kind of firmware running on it. It's possible
that this microcontroller were damaged?

I thought that maybe some kernel configuration issue too. Is it possible?

Thanks in advance.

Happy 2012.

Hi folks!

I've found another thread with a solution:

http://www.friendlyarm.net/forum/topic/534

I can't believe this problem is happening so often and FriendlyARM is doing
nothing to solve it...

Regards

Hello people. Would you mind mentioning which LCD is giving you a problem?
T35, N35, X35, W35? ARMWorks has a 2 year warranty, which is an advantage
over the eBay sources. First, have you reseated the FFC cables and the oval
connector? Also, there is a jumper to the left of the FFC connector. The
jumper connects the two pins most left - closest to the front of the board
with DB9, etc. The voltage on the right hand is for Hiteg MegaLCD and none
of the FriendlyARM displays at this time. Anyone have the jumper int he
wrong place?

Another solution here:

http://farm2440.blogspot.com.es/2011/09/display-turns-white.html

Best regards

Hi,

I bought mini2440 kit includes mini2440 and 7"LCD 1 GB RAM.

But the problem is I got LCD A70i-1501 rather than LCD A70i-1044.

So please let m know what are the differences between those two and mainly
whether they have solved white screen problem in the latest one are not.


Waiting for your valuable information

Thank you

Excuse-me because i dont speak inglish very well but I hope to help
someone. So the solution for this problem is simple,you just need to conect
the 5V(after of regulator) supply of main board direct to 5V on the lcd
board.This solve completly the problem.My board is a Micro 2440 lcd 7",for
this sdk i conect the pin 3 of U14 on mainboard to pin 3 of U4 on Lcd
Board.For other sdk i beleave that solve to.