When I built my work shop 3 years ago, I hired a Electrical contractor to come wire the shop correctly, and It was inspected by the state electrical inspector and stamped off with the little sticker they placed in the main circuit breaker box. Last Thursday I had a major failure of my brand new welder the ground lead to the welding bench became a high resistance connection, So the welder found a ground of least resistance thru my big belt sander neutral ground, which smoked the cords of the sander and the welder. OK moving, on we repaired those with new cords, and every thing worked good again until yesterday when my drill press decided to smoke its cord, and pop a breaker for the circuit its on. I then unplugged the drill press and reset the circuit breaker and nothing in the shop worked, nothing, all three circuits were dead. I then tripped the circuit breaker in the master breaker panel in the house that feeds the shop, and removed all the C/Bs in the shop panel. This is what I found. The advice I need is simple, do I need a whole new panel in the shop? or can this one be repaired?