Found this in an older thread -
"Are you testing that board with a load on it in a cabinet or just on your bench? ARII boards will ramp up the +5 to 14VDC if there is no voltage detected on the "sense" line. Do the ARII power mod and check it again..."
"If there's no board connected, R29 + R7 + R8 + R6 + R30 provide a resistive path from the regulated +5 to ground, and the resulting resistor divider puts voltages on +sense and -sense so everything regulates fine. If R29 or R30 is burned out, then the sense lines will float around, and +5V regulated can be just about any voltage, but there's still going to be ~5V between +sense and -sense...
So why do R29 and R30 burn out? Well, the ARII supplies cuurent through +5Reg and +5V Return (ie. ground), and the +sense and -sense are connected to +5 reg and ground at the board so the ARII can sense the actual voltages reaching the board, after resistive drops in the harness wiring, and connectors, which should always be less than the 10 ohms resistors in parallel with the sense paths. If, however, the resistance between +5 regulated or +5 return is significantly greater than that 10 ohms (ie. due to broken wires, burned edge connectors, bad pin connections), then the ARII will end up SUPPLYING current through the 10 ohm resistors, and since they're only rated at .25W, once more than about 150mA flows through them, they burn up, and the sense lines float."