my elegoo mars isnt printing anything

[Teasdalen]

My elegoo mars isn't printing at all, the other day it stopped mid print and ever since it wont do anything. The screen comes on, and the uv lights seem to be working. I've tried several different resins I've had success with in the past, but no luck. I tried almost everything I could find on the forums, re-aligning the build plate, making sure the usb wasnt full, using a new usb, ect... but still no luck. It seems very strange that the uv light comes on but there is no cured resin whatsoever, not even floating in the tank. my printer isn't even a year old.

[cliffyk]

In all likelihood if you have used the printer for > 3 to 4 months the LCD shutter has failed; though such failures are not usually as complete as you describe, however it is the first thing I'd check.

Remove the resin vat and platen assembly, a perform a dry-run "printing" of this file--LCDTest.stl (1.3 kB). You will have to use Chitubox to slice it and save to a .cbddlp or .ctb file.

The LCDTest.stl file defines a 120 x 68 x 2 mm solid block:



Placed a sheet of white paper over the LCD, and when "printed" in a dry run the LCD should display a relatively bright "white" 120 x 68 mm rectangle:



But more likely with a one-ear-old printer you will see a dim rectangle, or one marred by numerous dark spots caused by dead pixels and clusters of pixels in the LCD.

This is what mine looked like after just 3 months (300 hours or so) of operation:


If possible post some photos of what you see...

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Note: the built-in "exposure test" if just that, an exposure test--it is not a test of the complete LCD (it escapes me why such an onboard test is not available) , it "prints" a 10 x 68 mm frame around a solid central rectangle. The LCD can be in pretty bad shape and still look OK with the exposure test. Here's a shot of the exposure test using the same bad LCD as shown above:



The major flaw is visible once you know it's there, but the overall failure of the LCD is not "in your face"--and a bad LCD, one just dimmed overall, would appear to be fine to an inexperienced user.

[Teasdalen]

i thought about that and it doesnt seem to be the problem. i finally managed to get something to print and while the print wasnt too bad, there was alot of partially cured resin floating around in the tank. the resin floating in the tank wasnt hard but more of a yogurt consistency if that makes any sense. my supports were also a bit sloppy looking, some of the ones that were closer together even stated to fuse to each other.

[cliffyk]

Did you test the LCD as described above or did you just think about it? What you now describe are symptoms of a bad LCD. If it's more than 6 months olds, then it's time for a new one--even with just casual use...

[Teasdalen]

i did the paper test and nothing seemed out of the ordinary, but i couldnt get it to print that test file. i ordered a new lcd to see if that fixes the problem.

[cliffyk]

i did the paper test and nothing seemed out of the ordinary, but i couldnt get it to print that test file. i ordered a new lcd to see if that fixes the problem.

The file I linked is a .stl 3D model stereo-lithography "mesh" file, you need to load it into your slicing software (Chitubox or whatever you use); slice it, and save it as a printable instruction file. (.cbddlp or .ctb file extension depending on the age of your printer).

The built-in "exposure" test, if that is what you meant by "paper test", is incapable of properly testing the LCD.

[Teasdalen]

here are some photos that might help

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i sliced the file in chitubox, tried to print and got nothing. there was no cured resin at all in the tank

[cliffyk]

Guess I wasn't clear, I had asked that you perform a "dry" print, vat and platen removed an view the LCD screen during that dry run. However that it did not print anything, and based on your photos, your LCD is shot. Many permanently crystallized portions diminishing the transmitted light...