<p>So I am trying to fix a custom built 3D printer for my institute and am running into a problem I can't wrap my head around.</p>

<p>So the limit switches for Y-axis and Z-Axis work just fine, but the X-Axis does not. </p>

<p>All three switches are Makerbot (3-pin), and all three light up the LED when they get pressed. However the X-axis does not get recognized by Marlin. When I diagnose with <code>M119</code> command it does not show as triggered even though the LED is on. All the other ones do.</p>

<p>All three switches are connected to min (X-min, Y-min, and Z-min).</p>

<p>Could this be a firmware problem? Or perhaps my RAMPS 1.4 has burned out the X-axis signaling? (I doubt this because the LED on the switch still turns on).</p>

<p>Let me know if you need any more info to diagnose the problem.</p>

<p><em>P.S. I have also replaced the X-Axis limit switch with a brand new one and the same result happens: LED turns on upon activation but it doesn't get recognized by the machine.</em></p>

[{'answer_id': 7815, 'author': '0scar', 'author_id': 5740, 'author_profile': 'https://3dprinting.stackexchange.com/users/5740', 'pm_score': 0, 'selected': False, 'text': '<p>To rule out problem with the switches itself, you can change the Z-min and swap it with the Y- or Z-min. Once you found out that you get the same issues you know that your X endstop module is working (unless they both are faulty, but the odds are small for that), but the signal change is not registered by the board. This could be a faulty port/pin of the X-min port / attached microprocessor pin. What you could do to try to diagnose that is using the X-max header on the board. In order to use that header for X-min, you need to change some code in <a href="https://github.com/MarlinFirmware/Marlin/blob/1.1.x/Marlin/pins_RAMPS.h" rel="nofollow noreferrer">pins_RAMPS.h</a>, change:</p>\n\n<pre>\n//\n// Limit Switches\n//\n#define X_MIN_PIN           3\n#ifndef X_MAX_PIN\n  #define X_MAX_PIN         2\n#endif\n</pre>\n\n<p>to:</p>\n\n<pre>\n//\n// Limit Switches\n//\n#define X_MIN_PIN           2\n#ifndef X_MAX_PIN\n  #define X_MAX_PIN         3\n#endif\n</pre>\n\n<p>Recompile and upload. Please use the latest sources, 1.1.9, 1.1.0 is very old.</p>\n'}, {'answer_id': 7819, 'author': 'Pᴀᴜʟsᴛᴇʀ2', 'author_id': 11242, 'author_profile': 'https://3dprinting.stackexchange.com/users/11242', 'pm_score': 1, 'selected': False, 'text': "<p>Considering you're having issues with the board, and the limit switches appear to be registering, but the board isn't doing anything about it, a first good step would be to update the firmware to 1.1.9 as @0scar states. If the update in the firmware doesn't do the trick, then move on to doing as he suggests with changing the Xmax/min stuff around. This just seems like a good first logical step to getting it fixed.</p>\n"}]
['https://3dprinting.stackexchange.com/questions/7811', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/14007/']