I have a 1995 ComfortMaker, forced air, NG, 80% efficient, furnace with a 50A50-110 control board. The original board was replaced in year 3 under warranty. I am now having regular problems with the furnace going out. The trouble light on the control board blinks from one to six at varying times indicating different problems, the usual display is for an open or closed low pressure switch. If I turn the unit off at the circuit switch and wait, I can often get the unit back on. I've had the various swithches checked and even replaced the low pressure sensor and switch to no avail. Interestingly, if I torque the wire harness connecting into the control board the problem seems to go away. Now I have wedged the wire harness and have not had a failure for over two weeks. I do fear that this will not last. The connections have been cleaned on the harness and the pegs of the control board. If I remove the wedge or jerk the connection the problem recurs. The replacement board would be a 50A55-843. Does it sound like I need a new control board?

Could be a defective connector or a crack in the board at the connector. Without being there it is impossible to tell.

Unless you are comfortable with soldering connections, then I would replace the board as you have certainly determined the problem...