<p>A couple of weeks ago I have successfully built a 3D Printer and Printed an XYZ Calibration Cube with ABS material at bed temperature 80 °C.</p>
<p>Next Day I tried bed heating at bed temperature 80 °C,</p>
<blockquote>
<p>Screen is blank</p>
</blockquote>
<p>and it's not heating at all and showing Following error.</p>
<blockquote>
<p>Bed Heating Failed
Printer Halted
Please Reset</p>
</blockquote>
<h3>Specification board</h3>
<p>I use a RAMPS 1.4 running Marlin 1.1.X</p>
<h3>Troubleshooting</h3>
<p>I searched on Google and tried possible solutions but they are not working.</p>
<ol>
<li>I changed the thermistor and nothing happened, the old thermistor is also showing the same temperature.</li>
<li>I connected 12V Supply Positive to SMPS (Switched-Mode Power Supply) and Negative to RAMPS 1.4 and not working</li>
<li>I checked the Voltage at heat bed it's showing zero in spite connecting to SMPS</li>
</ol>
<p>Please let me know how can I fix the problem?</p>
<p><a href="https://i.stack.imgur.com/vMlmM.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vMlmM.jpg" alt="I have blank image after pressing 80 °C" /></a></p>

[{'answer_id': 8168, 'author': 'Chaos_99', 'author_id': 14446, 'author_profile': 'https://3dprinting.stackexchange.com/users/14446', 'pm_score': 2, 'selected': False, 'text': "<p>Check that your heated bed is still working: </p>\n\n<ul>\n<li>Measure the resistance of your heated bed. It depends an the power\nrating of the bed, but 12V beds usually have values &lt;3 Ohms. That's\nhard to measure for cheap multimeters, but you just need to check\nthat it's not MOhms which would indicate a broken heated bed.</li>\n<li>Your heated bed could also have a short. That's hard to measure, as &lt;3Ohms are already 'almost a short'. You'll only notice because your\nbed will not get warm, but the wires, connectors and elements on the\nRAMPS will get even hotter. Marlin should detect this and switch off\nafter a few seconds.</li>\n<li>Check your thermistor. Seems you already did that.</li>\n<li>Check your RAMPS by measuring the voltage on the bed connector while setting the bed to heat up. You should see 12V, at least in the\nfrist few seconds.</li>\n</ul>\n"}, {'answer_id': 16384, 'author': 'Zeiss Ikon', 'author_id': 28508, 'author_profile': 'https://3dprinting.stackexchange.com/users/28508', 'pm_score': 0, 'selected': False, 'text': "<p>I've just been reading <em>3D Printing Failures: 2020 Edition</em> by Sean Arandy and David Feeney -- one of the things they really harp on is that the high current connectors on the RAMPS board for the bed heat are grossly under-rated -- that is, they're connectors rated for about 4-5 A, while the bed needs to draw about twice that to heat a rated power level.  Their recommendation is to switch this connector on the RAMPS board for one rated at a minimum of 16 A to ensure it has a safety margin over the most current a 12V bed heater will draw.</p>\n<p>If you use an e-reader, you may want to consider downloading this book -- it's only ten dollars for Kindle (also available on Kindle Unlimited), or twenty for a paper copy, and to my eye, it's worth having.</p>\n"}]
['https://3dprinting.stackexchange.com/questions/8162', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/14440/']