[SOLVED] Screen unreadable for certain fonts: normal?

[mougino]

Hello all, I have big problems with my Gamebuino screen, I don't know if others had them and managed to fix them.

First off, I need to say that I carefully read the wiki (getting started, and troubleshooting) but to no avail.

The physical connection of my screen to the pcb is originally very bad: I have to operate the Gamebuino without the back case, and with a sim-card acting as a lever in the top left opening where the screen is snapped to be able to see anything.
Not doing that, my screen is 100% blank all the time in all screens (bootloader title, game grid, or in any game).
Doing that though is sometimes not enough, and that's the purpose of my question:

Most fixed screens, typically title screens (bootloader or games), have a good contrast and display perfectly. But as soon as there is an animation, some horizontal lines appear lighter than the rest, and a little flickering, in other words they look like painted in the third (gray) color I read in some topics of this forum.

But that's not the worse: in screens full of text with zero animation (e.g. my gamebook engine) using font5x7 the display is as perfect as the title screen: I can see deeply contrasted black pixels. Using font3x5 it is still readable, but the contrast is not so good: there's a little flickering and the whole text on screen looks grayish...
Finally using font3x3 the whole screen is totally unreadable! tilting the Gamebuino so that my eyes do an angle of a few degrees with the screen plan, I can hardly see that the screen is filled with (almost white) characters, but in normal reading conditions the screen appears empty >_<

Do these symptoms ring a bell to anyone ? Is the problem known and fixable ?

Few final words: I also tried to change the contrast / backlight settings but that didn't change anything. I also thought the light sensor could be the cause of the blank display so I tried different configurations: covered, in shadow, under deep light but alas again to no avail. And I also thought the battery was causing trouble so I recharged it at 100% (until the most right led was on), all for the same results.

Thanks for any feedback !
Nicolas

[mougino]

Ok, I give up. It seems my screen is malfunctioning, I can't use my Gamebuino as is, it's simply unreadable
So I guess I'll try ordering another Nokia 5110 screen on eBay...
What annoys me more is that I'm very close to finishing my gamebook engine, but I have no way to test it in "live" mode

Nicolas

[erico]

Mine has started reacting like that a month ago.
The only thing I did was that I removed the piece of plastic that holds the screen in place, but that phenomena just started weeks after it.
Another thing is that my on/off switch is having a strange behaviour, like if I touch it, it turns the gamebuino off.

I suspect it is all a combination of things, so I´m going to do the following:
1-update firmware to the latest (mine is the indiegogo version)
2-check the contacts of the screen, clean it up with rubber and probably use the plastic or a rubber piece to force it into place for a while.
3-then on/off switch I suspect has developed problems in contact so I have to check that too.

I will let you know the results, but I´m certain I can fix it. It always worked even without the case.

[erico]

I´m going to run a fix right now, let´s see how it goes...

just a final note about the behaviors:

When I turn it on, on the SD card screen, I get a light line then a dark(normal) line and repeat all the way down.
The first light line is particularly more faint, the others are all the same intensity.

When I get to the text menu, and my first page is full, it is similar to the intro, when I advance pages and there is a couple entries only, it is dark.
Strange enough, when I run LunarRun, it all is fine, even the almost full black screens.

[erico]

So I opened it, took the screen off carefully, used normal white rubber to clean the PCB part connector to the screen, I just erased it a few times just in case and carefully blew the rubber particles off it (don´t spit!).

I did similar thing to the on/off component but it is welded and I could not do much.

I reattached the piece of plastic that forces the screen together with the case.
Screen works fine now, all ok under any condition.

My on/off switch is still buged, sometimes when ON, it is OFF, and moving it around a little I can get it to work.
After it is working, it is all fine. Thanks it is located on a place that you don´t accidentally touch.
When turning OFF, it goes OFF before the switch is pushed right.

I can´t seem to figure out if it is a problem with the switch or with the weld.
But it is working and I can safely play, so it is all fine.

[mougino]

Wooow thanks so much Erico !
I already dismounted the screen several times before, but I never noticed the contact was in the top-middle back rubber.. I always cleaned the clippers on the 4 corners of the screen, naively thinking they were the ones making the contact
Cleaning the actual PCB connector and nowhere else did solve all my problems reported above!! The $3 replacement screen I ordered will be useless, but more important I can test my gamebook engine in live conditions

Nicolas

[erico]

Glad to hear it is all fine!

[jonnection]

.. I always cleaned the clippers on the 4 corners of the screen, naively thinking they were the ones making the contact s

You have much to learn about electronics, young padawan