Firmware update failed, display shows rectangle only!

[OleOhlsen]

Thank you for your nice patience with me!

I didn't know much about 3D printing before I bought the printer. I looked for tests at the web, and this was recommended as a good price-performance ratio, so I ordered it.
To mount the set cost me 4 hours (youtube videos, no paper instruction was with the printer, except a parts list), to learn how to print, days. The result was bad. I found out that the feeder was broken, and bought a new one (Geeetech aluminium), but my print result was still bad.
So I tried to figure out how to set cura, which made the result better, but not good. Someone at the web recommend me to update firmware, and (how ever to do) configure the printer.
Thats where I'm now.

I'm ready to learn, but I couldn't find out what exactly my printer is. All I know is what was at the amazon ad "Geeetech 3D Drucker Acrylic Prusa I3 Pro B", and on the board is GT2560 Rev A+, I don't know what all the shortcut in Marlin mean, and which part it belong to.

[OleOhlsen]

Yeahhh, I (you, we) got it! Display shows what it should!!!
Thank you so much!!!!

Now I have to configure all. Hope I will find some information....

[OleOhlsen]

I already doing a test print, and so far it is finished it looks MUCH better than before!!!
Thank you for sharing the firmware!

Only one issue is left: It does not accept my SD card. I already tried all advises I found at the web, but no success.
I tried format on my mac, at my Canon camera (like some suggested) and with SDCard Formatter software. Is shows Media at LCD screen, but when I click it, SD card is not found.

[OleOhlsen]

No, it didn't work with the old version. I will try another card, I have one in my camera.
If the card slot would be defect it should not show Media at start screen.