When I connect my USB to laptop and give prints to 3d printer from laptop, then only my display works/I can control printing using display. But as soon as I remove USB my printing gets OFF and display aslo goes OFF. What could be the reason? I am using mega2560, ramps1.4, reprap full graphics controller,12V power supply for my 3D printer. I check my voltage braker of Arduino connecting USB to laptop and it shows 2.9V and 4.9 V at its 2 pins. Is this OK? I checked 5v pins and 3.3V pins on mega2560 and it shows correct reading. But when I checked 5V pins on ramps1.4 It is showing lower voltage. 12V pins on ramps1.4 shows correct reading. How to troubleshoot this problem? I am unable to find where the problem lies exactly. What should I check to relocate my problem? https://reprap.org/forum/read.php?415,876105,876105#msg-876105 Wed, 12 Aug 2026 02:32:10 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?415,876105,876450#msg-876450 https://reprap.org/forum/read.php?415,876105,876450#msg-876450 One thing I observed that when I simply plug in the USB to laptop, display gets 4.7V but still it doesn't shows any text until I click "Connect" in pronterface.
What does this mean? How can I connect automatically to Printer without using pronterface?]]> pvishalp19 Firmware - Marlin Sun, 23 Aug 2020 03:36:13 -0400 https://reprap.org/forum/read.php?415,876105,876152#msg-876152 https://reprap.org/forum/read.php?415,876105,876152#msg-876152 [reprap.org]

I assume you are using the board with 12v PSU connected. Is there a difference in the voltage you read on the GND and VCC pins of the Ramps board going to the LCD panel with USB connected and disconnected?]]> Ohmarinus Firmware - Marlin Sun, 16 Aug 2020 05:51:29 -0400 https://reprap.org/forum/read.php?415,876105,876124#msg-876124 https://reprap.org/forum/read.php?415,876105,876124#msg-876124 If there is difference between reading with USB and without USB , what does that mean?]]> pvishalp19 Firmware - Marlin Sat, 15 Aug 2020 16:11:09 -0400 https://reprap.org/forum/read.php?415,876105,876107#msg-876107 https://reprap.org/forum/read.php?415,876105,876107#msg-876107
Did you measure the voltage over the LCD power lines with and without USB plugged in?]]> Ohmarinus Firmware - Marlin Sat, 15 Aug 2020 02:34:44 -0400 https://reprap.org/forum/read.php?415,876105,876106#msg-876106 https://reprap.org/forum/read.php?415,876105,876106#msg-876106 The issue which I am facing is this because of Marlin settings or purely hardware/electric issue?]]> pvishalp19 Firmware - Marlin Sat, 15 Aug 2020 00:07:52 -0400 https://reprap.org/forum/read.php?415,876105,876105#msg-876105 https://reprap.org/forum/read.php?415,876105,876105#msg-876105 But as soon as I remove USB my printing gets OFF and display aslo goes OFF.

What could be the reason? I am using mega2560, ramps1.4, reprap full graphics controller,12V power supply for my 3D printer.

I check my voltage braker of Arduino connecting USB to laptop and it shows 2.9V and 4.9 V at its 2 pins. Is this OK?
I checked 5v pins and 3.3V pins on mega2560 and it shows correct reading.
But when I checked 5V pins on ramps1.4 It is showing lower voltage. 12V pins on ramps1.4 shows correct reading.

How to troubleshoot this problem? I am unable to find where the problem lies exactly. What should I check to relocate my problem?]]> pvishalp19 Firmware - Marlin Sat, 15 Aug 2020 00:05:20 -0400