<p>ISSUE: Stepper motors are not working when connected with RAMPS 1.4.</p>

<p>OBSERVATION: The LED lights(LED 2,3,4) in the RAMPS 1.4 is not powering up.</p>

<p>PRACTICES: I use Arduino Mega 2560 and installed Marlin firmware in it. And I bought a RAMPS 1.4 in a local electronic dealer. I placed the RAMPS over Arduino Mega 2560. For testing I just connected 2 NEMA 17 stepper motors with RAMPS. When USB port connection is given from laptop to Arduino board, a LED light is ON in Arduino board (L) and in RAMPS (LED 1). I use SMPS 12&nbsp;V 20&nbsp;A as a PSU for RAMPS. But in RAMPS the LED 2, 3, 4 are not switched ON. I checked the input voltage to the RAMPS using micrometer and it shows 11.75&nbsp;V. But there is no output from the RAMPS.</p>

<p>Also I installed and tried Repetier firmware and Grbl but it doesn't work. And I use Windows 10 pro 64 bit OS.</p>

<p>When I flashed Arduino with Grbl, in this case all of the LEDs on the Arduino and RAMPS 1.4 are switched ON. I use Candle GRBL software to test the stepper motors.</p>

<p>And I replaced and tested with another RAMPS which is bought from Amazon but the problem remains unchanged.</p>

<p>Kindly give some suggestions at the earliest.</p>

<p>I have attached the images of my circuit connection:</p>

<p><a href="https://i.imgur.com/k39rd7t.jpg" rel="nofollow noreferrer"><img src="https://i.imgur.com/k39rd7t.jpg" alt="i.imgur.com/k39rd7t.jpg"></a></p>

<p><a href="https://i.imgur.com/OPPuElQ.jpg" rel="nofollow noreferrer"><img src="https://i.imgur.com/OPPuElQ.jpg" alt="i.imgur.com/OPPuElQ.jpg"></a></p>

<p><a href="https://i.imgur.com/mM3BIEn.jpg" rel="nofollow noreferrer"><img src="https://i.imgur.com/mM3BIEn.jpg" alt="i.imgur.com/mM3BIEn.jpg"></a> </p>

<p>Board selection in Marlin:</p>

<pre><code>#ifndef MOTHERBOARD 
#define MOTHERBOARD BOARD_RAMPS_14_EFB 
#endif 
</code></pre>

<h3>Additional clarifications</h3>

<p>In response to Professor's questions:</p>

<ol>
<li>Yes the stepper drivers are connected correctly </li>
<li>Yes the stepper wiring is accurate (2B 2A 1A 1B) as per mentioned in the Ramps 1.4. </li>
<li>No there is no voltage input to stepper motor. But there is 12V input to Ramps 1.4. </li>
<li>Disabled cold extrusion </li>
<li>No, the firmware is not set to no move before homing (issue G28 first) </li>
<li>Yes, pins are set correctly for your board in Marlin</li>
</ol>

[{'answer_id': 6745, 'author': 'profesor79', 'author_id': 9730, 'author_profile': 'https://3dprinting.stackexchange.com/users/9730', 'pm_score': 1, 'selected': False, 'text': "<p>to help you to solve this problem - please see my checklist</p>\n\n<ol>\n<li>are the stepper drivers connected correctly (pin1 to pin1)?</li>\n<li>stepper wiring is accurate (1a-1a..2b-2b)?</li>\n<li>is there enough voltage provided to the steppers (regulate)?</li>\n<li>if you are trying to move E0 or E1 then you need to disable cold extrusion as that stops rotation (waiting for 170C deg on the nozzle)</li>\n<li>is the firmware set to no move before homing (issue G28 first)?</li>\n<li>are pins set correctly for your board in Marlin?</li>\n</ol>\n\n<p>the led's are set on my ramps as they are mostly giving a stutus for heater fan and bed, so grbl software could use those pins differently</p>\n"}, {'answer_id': 7175, 'author': 'Baalaji V', 'author_id': 12765, 'author_profile': 'https://3dprinting.stackexchange.com/users/12765', 'pm_score': 2, 'selected': False, 'text': "<p>I actually thought the problem is in the electronic circuit but the problem is the baud rate. I initially took the baud rate as 115200 but later. after someone's suggestion, I changed it to 250000 and now it's fine.</p>\n"}]
['https://3dprinting.stackexchange.com/questions/6744', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/12765/']