I have a van dorn 150 model 150-RS-12F-1789 That the position display is not reading correctly. It won't zero out and stays at 0.25. It also won't count up correctly. When rotating the screw back it will throw out random numbers and the screw ends up going all the way back to the end. There is a fuse on board 29 that is labeled F4-HLK that is a 2.5amp glass buss fuse. It keeps blowing. I tried a 3 and a 5 amp but they blow almost rightaway. I wonder if the board that the position selector switches and display and position sensor are wired into is bad. The switch was replaced recently cause it wasn't reading at all and it worked for like a month.Anyone familiar with this machine? What does fuse F4-HLK go to on board 29? This is the board that is nothing but a row of fuses when looking in the cabinet on the left door that is nothing but circuit boards. I can't locate a manual online. This machine has always had memory issues with forgetting it's position on the shot size but it's gotten worse. I'll make a video then post the youtube link here so you can see what I'm talking about.