you should be able to check voltage from L1A to L2AX which is the power supply input to the PSC board. it should operate fine with voltages above 105VAC. If you are watching the board, if brown out led comes on, then LED2 should come on and stay on until the voltage at L1A to L2AX comes back to tolerance. then the brown out LED will stay on even though the voltage has come back into tolerance. this is why you often see the brown out led on when you look at the board, and the car is running fine. If you are seeing brown out LED1 come on, then LED2 turn on then off again you are either dropping input voltage, or something is dragging down the voltage at terminal SS. L2AX feeds SS through the S2 switch, so if SS grounds momentarily, L2AX will drop and the brown out sequence will start. However, if you are only seeing LED2 come on and then reset, you could have a bad input or output card that is dragging down the voltages of the system, causing led2 to reset the cpu. You would not want to try and disable the brown out circuit, this is a safety feature that essentially shuts off the cpu thus clearing all outputs. I have never actually seen a brown out cause a shutdown in the field. I have only seen the led on when we go to a miprom job. it is something that we have all seen and usually just reset it and go on about our business. If you guys actually witnessed brown out led come on and stop the car in flight, and the power is good, i would look at the SS line.
Last edited by Scott Davidson; 05/13/11 12:19 AM.