Nonlinear boundary value differential equations are usually solved with the 'shooting method'. In this technique, the initial conditions are adjusted until the boundary conditions at the other boundary are satisfied. In situations in which the shooting method fails, the iterative 'relaxation' method can be used. Initial guesses at the solution are improved repeatedly. The relaxation method can be implemented using 'quasi-linearization'. The differential equation is linearized about the guessed solution and the linearized boundary value problem is solved. This technique can be implemented in a very straight-forward fashion in Mathematica because the numerical solutions to differential equations are interpolating functions. Quasi-linearization is first demonstrated with a single differential equation and then with the 5 coupled differential equations which describe a p-n junction.This submission is an update to a previous submission (see URL below). I have updated the code, improved the ...