<p>Recycling a Robin Nano board to build a 3D printer using an old computer PSU (300 W), it only boots on when I have no endstops pugged in at all or if I trigger all the ones I have plugged. At the moment I release them the screen goes off (but the fan of the PSU is still on). Does anyone have any clue about what's going on ?</p>

[{'answer_id': 11414, 'author': 'Cobactan', 'author_id': 14785, 'author_profile': 'https://3dprinting.stackexchange.com/users/14785', 'pm_score': 2, 'selected': False, 'text': "<p>It ended up I had like super cheap endstops that were actually shorting VCC to GND, as suspected by r_ahlskog. Just bought other ones and now it's working fine.</p>\n"}, {'answer_id': 11419, 'author': 'r_ahlskog', 'author_id': 14957, 'author_profile': 'https://3dprinting.stackexchange.com/users/14957', 'pm_score': 2, 'selected': False, 'text': '<p>From your fault description of printer logic board losing power when endstops are released it sounds to me like those endstops are shorting VCC to GND when not pressed. That the fault also goes away when the endstops are unplugged reinforces this.</p>\n\n<p>I guess the logic board has its own protected regulator because otherwise you would be shorting out the power supply and that would also turn itself off after likely causing a lot of damage to the logic board.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/11210', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/14785/']