Form 1: print offset problem

https://www.dropbox.com/s/93vc7yhtjr9k3po/Form1.jpg?dl=0

I have a print offset problem with my old Form 1: the black piece of preform is printed where the white piece is.
how to adjust this shift?
The offset is 15mm !!

I think there’s a setting in Preform to adjust X/Y offset for the Form1. Many years ago, after I took my Form1+ apart to clean the optics, the prints were offset about 5mm to the right. If I printed at the far right of the build platform, the model was actually 5mm offset past the edge of the build platform. There was an adjustment I was able to make to correct it But it’s been many years, my Form1 is no longer in use, I can’t recall the details.

Many thanks, but i’m looking for the … details.
I see nothing in preform ( i use preform 2.14)

i have find the option, but what is the right direction for me ? - Y ou +Y ?

No idea. Put something small in the center of the build plate and then change the offset to 15mm and print. If the part isn’t in the center, change the offset to -15 and try again.