all prints are failing suddenly

[cliffyk]

The LCD is bad--almost guaranteed. I have been through this twice now--with both of my Mars' machines after three months or so the LCDs get sluggish and develop small (and sometimes not so small) opaque spots and an overall  "crazed" appearance. The LCD in my newest printer (I received on May 4, 2020) failed relatively suddenly over the last week, almost 3 months to thy day after going into service.

Here's a cruumy photo of what I found last evening when perfoming a LCD test by "printing" (vat and platen removed) a 68 mm x 120 mm x 2 mm block (I will see if I can get a better photo later today.):



Note the large cluster of bad pixels and the numerous other clusters and individual dark pixels. Amazon says a new LCD screen is coming today ($29.99 w/ overnight shipping with a Prime account). I will see if I can get a better photo later today.

Unfortunately the built-in "exposure test" cannot reveal this as all it projects is a frame of  "on" pixels surrounding a largish central box of "off" pixels that encompasses the bulk (and most used portion) of the display. Using the exposure test would not have revealed the flaws show above.

To truly test the LCD you need to print a 120 x 68 mm block as did I:



Here is a link to an .stl file containing that model...