HELP! Not getting very far with the limit switches on this screen. What I am trying to do is get the screen to drop to a required hight when I activate my amp. Currently I am using the up/down rocker switch as a temp to set it up then change to a 12 volt trigger later. First off I sm trying to set the drop, so am using the alan key screw accessed through the bottom of the case at the back, where the screen appears from. Turn the screw but sofar nothing seems to happen with the drop. Is there a number of times you have to turn it or something I am missing? AT the moment when you press the down switch the screen drops to full length the retracts itself to about half way and stops. Heigh adjust as I understand sets the height limit so it will turn itself off when it reaches the top eg retracted fully. Again turned it so many times now when it does retract (press the up switch) it does not cut out just keeps the motor running. To sum up I have turned so many things so many times I am in a right mess so any help would be much appreciated. Thanks, sorry its such a long post.