becm??rear window not set

ok i have had a fault with the rear win dow not goin up ,goes down fine .. i have now replaced my top board with a donor board and it works .. but wont set. all others are fine i cant see any problems with starting or anything ... is this safe to run on a replacement top board and does anyone have any idea why this 1 window wont set ?? thanks in advance

Sounds obviously, but have you done the old: press button to lower window to full lowest position and then immediately press the button up to the highest position in one single movement?

That should set any window or sunroof. It must in all cases move through all extremes and back again in a single movement to set.

yeah ive set all the others