12864 lcd screem not working correctly

i have a solid blue screen on my 12864 full graphics controller lcd...ive reloaded firmware ive downloaded marlin from somewhere on the forum that was supposed to run but didn't...i have a folger tech prusa i3 2020..im getting sick of this thing and trying to get everything to work correctly. I'm about to junk it..can somone please give me their marlin firmware "that works" so i can get this usable..thank you

I just recently went through the hassle to get my 12864 working. These are the things to check for:

• Make sure your EXP1 and EXP2 connectors are not swapped
• Some have reported the silkscreen on the LCD PCB is incorrect and that in addition to switching EXP1 with EXP2, they needed to rotate the connectors 180 degrees
• In Marlin configuration make sure you have the line #define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER uncommented
• Make sure you have included the U8glib library in the Arduino IDE

Thats the basic checklist. I would suggest taking a fresh, clean copy of Marlin (I'm using the development branch myself) and first just setting the correct motherboard and movement settings. Then upload the firmware and make sure it all works. Next add the U8glib library to Arduino IDE and uncomment #define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER (by deleting "//" from the beginning of the line)
Now compile, upload and check if it works. If not, swap out EXP1 and EXP2 on the display controller

Rotate the connectors??? They are supposed tononoy go in one way...do I cut that notch off or something...obviously I would check everything else first...much appreciated

Yeah, they are *supposed* to go one way, but some idiot somewhere made up a batch with connectors installed backwards . . . my plain controller and 12864 are keyed exactly opposite. Typically, if they are backwards, you don't get the backlight at all, and (fortunately) the pinouts prevent any damage from reversal.

- Tim

Edited 1 time(s). Last edit at 08/12/2015 11:12AM by tadawson.

how can i tell if they are backwards..ive switched the connectors and i get a light either way although when they are connected "correctly" the blue screen is dimmer. Btw i had a 2004 controller that worked..The only reason i change is because the knob would not let me switch through the prompts.

If you rotate the encoder and get normal feedback clicks, that also confirms that your are correct. If you have the skills, a meter a d the schematics will let you determine the actual pin1 as well - the Ext1 and Ext2 labels have not been reported to have been seen wrong that I am aware of.

- Tim

When you look at the display from different angles, does it always look steady blue all the way over? If so, then the contrast needs adjusting. Some people find they have to add a resistor to the board to get the contrast in the viewable range.

If you can see pixels over most of the display, with a solid blue margin around the edge, then the contrast is OK and it's a connection or firmware issue.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I've tried the contrast adjustment knob and goes from bright blue to dark blue...its a solid blue screen all the time..I'll post pics of it too later..I'm currently at work...if it helps I bought the screen from Folger tech...

There's also a contrast adjustment pot under the LCD. I used a bent paperclip with a flatten edge to get under the LCD to adjust.

so I started with a fresh marlin version directly from folger tech website... still solid blue screen but the beeping works when I depress the button..still no graphics..does this help

Either you uncommented the wrong device in Configuration.h, or you have the contrast issue most likely . . . .

- Tim

I figured it out..All is working and now I'm a happy camper!!!!! I ended up updating marlin from the (old) one folger is using.. It also ended up being a contrast issue...I appreciate everyones help here!!!!!!

I also have a folger printer and recently got a screen to upgrade it. I am having the same problems. Would you care to share the firmware files?

Edited 1 time(s). Last edit at 10/15/2015 05:55AM by bgllvr.