Hello everyone so, today i got my new LCD controller. I connected it and made adjustment in Marlin firmware. Without the USB connected the LCD didn't worked so I suspected there's something wrong with Arduino mega 2650. And it is - it doesn't work even when additional adapter is plugged (5 V pin is fried or something?), but it works normally connected via USB. But here is the problem - the LCD should work when Arduino is connected to computer - and it kinda does but it shows blue screen without any characters. And no, it's not contrast. Any ideas? I attached an image of the LCD when Arduino is plugged via USB. I had problems with Ramps 1.4 before - D9 pin was fried (I was using it for the fan) so i soldered a new one. After a while I thought the thermistor was going nuts - showing a temperature of 60 degrees celsius with heatbed not working, but with a new thermistor it was the same story - so it's Ramps but I don't know why. And today I discovered the Arduino is not working properly as described above. Thanks in advance! :) https://reprap.org/forum/read.php?406,508226,508226#msg-508226 Thu, 16 Jul 2026 22:21:10 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?406,508226,543397#msg-543397 https://reprap.org/forum/read.php?406,508226,543397#msg-543397 This Video helped me set up mine. Also the contrast knob is very touchy. Bumping mine can mess up the contrast making text unreadable.]]> gmckee Prusa i3 and variants Fri, 07 Aug 2015 13:38:16 -0400 https://reprap.org/forum/read.php?406,508226,543376#msg-543376 https://reprap.org/forum/read.php?406,508226,543376#msg-543376 paultnl Prusa i3 and variants Fri, 07 Aug 2015 12:33:33 -0400 https://reprap.org/forum/read.php?406,508226,542540#msg-542540 https://reprap.org/forum/read.php?406,508226,542540#msg-542540
Bill]]> robodog Prusa i3 and variants Wed, 05 Aug 2015 17:51:20 -0400 https://reprap.org/forum/read.php?406,508226,508226#msg-508226 https://reprap.org/forum/read.php?406,508226,508226#msg-508226
so, today i got my new LCD controller. I connected it and made adjustment in Marlin firmware.

Without the USB connected the LCD didn't worked so I suspected there's something wrong with Arduino mega 2650. And it is - it doesn't work even when additional adapter is plugged (5 V pin is fried or something?), but it works normally connected via USB.

But here is the problem - the LCD should work when Arduino is connected to computer - and it kinda does but it shows blue screen without any characters. And no, it's not contrast.

Any ideas? I attached an image of the LCD when Arduino is plugged via USB.

I had problems with Ramps 1.4 before - D9 pin was fried (I was using it for the fan) so i soldered a new one. After a while I thought the thermistor was going nuts - showing a temperature of 60 degrees celsius with heatbed not working, but with a new thermistor it was the same story - so it's Ramps but I don't know why. And today I discovered the Arduino is not working properly as described above.

Thanks in advance! :)]]> Smatta Prusa i3 and variants Tue, 12 May 2015 14:21:13 -0400