Printing on 0 to 2mm and after nothing

402 / 5 000
On Halot Mage Pro
My 12mm high model prints only print up to 2mm at most.
The process runs normally, but there is no layer cure.
Later I realized that the UV source was very weak, restarting the printer seems to return it to normal. But does not allow printing more than 2mm.

Is the UV source or the power supply at fault?

After opening the back cover, the UV lamp lights up correctly throughout the cycle.

So I checked the screen, and I confirm that it remains black around the 50th layer. Any idea? The same file works on another printer in the same series (Halot Mage Pro)