UV light doesn't turn on when printing

[Innocent]

I have recently purchased an Elegoo Mars Pro. I've levelled everything properly, but it didn't work. When I started printing, the build platform went down and started making a grinding noise. I've checked formus and they said that it's a levelling issue. So I had to level it again. I've done everything according to the instructions. Now apparently I didn't check if the UV light was displaying the sliced image when printing... When doing the exposure test the UV light turns on, and also with the cleaning option. But I tried to remove the vat and print with a piece of paper and nothing turns on... please help.

Thank you

[cliffyk]

If you remove the platen (buld plate) assembly and vat. and try to "print' a file does the trolley descend, stop, rise slightly and descend a bit again--and not make the grinding noise?

In normal operation:

• The trolley descends and stops when the "flag' at its bottom interrupts the optical limit switch (this is the hardware lower limit of travel);
  
• The trolley then rises a bit;
  
• The trolley once again descends a bit to stop at a point one layer thickness' above the hardware lower limit;
  

If it behaves as above without the platen in place it has to be the vertical position adjustment of the platen that is creating the noise (the platen is bottoming out and the stepper motor is "cogging").

Are you 100% sure you fully loosened both locking screws when you performed the alignment?

With the locking screws loose will the platen move "upward"in the holder (against a light spring pressure)?

The lamp not coming on is most likely another issue but let's deal with that once the motion issues are resolved...

[Innocent]

It was an issue with the leveling, I've solved it, now printing the first print
Anyway, thank you!

---

If you remove the platen (buld plate) assembly and vat. and try to "print' a file does the trolley descend, stop, rise slightly and descend a bit again--and not make the grinding noise?

In normal operation:

• The trolley descends and stops when the "flag' at its bottom interrupts the optical limit switch (this is the hardware lower limit of travel);
  
• The trolley then rises a bit;
  
• The trolley once again descends a bit to stop at a point one layer thickness' above the hardware lower limit;
  

If it behaves as above without the platen in place it has to be the vertical position adjustment of the platen that is creating the noise (the platen is bottoming out and the stepper motor is "cogging").

Are you 100% sure you fully loosened both locking screws when you performed the alignment?

With the locking screws loose will the platen move "upward"in the holder (against a light spring pressure)?

The lamp not coming on is most likely another issue but let's deal with that once the motion issues are resolved...