Hello everyone I was wondering if anyone could help with this control board. I have a friend that own several hog barns and there switches and rotary encoders are always going out. So I started fixing them and now he dropped off several and I have a couple that have same problem. They don't light up the display. I can't tell what is going on. I tested the display and it has a common anode and with meter all digits lit up individually. I have plugged other boards into the same power supply board and they worked so it has to be with that board. Could someone give me a few hints on where best place to look. I guess no one would have any idea if there would be any place to get a schematic for this would there? That would help me learn how they are all working together. They hook together by ribbon cable at J4. Also there are 2 scr 's on the bottom of the power supply board attached to a heatsink, what is there function? And if I'm going to be working with these types of circuits do I have to have an oscilloscope? If so what kind and MHZ. I was kinda looking at some Rigols. I don't know how to use them yet, I just know to watch where you attach the ground clip if it not isolated. Any help is always appreciated. Sorry if I'm kinda all over the place...