You can divert power to weapons (if you don't already do so) to tide you over until you can afford a better power distributor.
Another factor to consider is fire-angle. At least on the Viper, the bottom two hard points have a limited shooting angle with gimballed weapons. When I'm fighting, sometimes the left or right fires if the target is slightly off to one side, and sometimes neither fires because the target is slightly above me and so obscured by the ship's hull. Took me a while to figure out why nothing was firing!