Light Problem?

not mine but a friends,light tripped a fuse went to have a look when he plugs ballast in it hums like normal(magnetic ballast) but when he plugs the lead in(female/male plug) it trips there cant be a lot to go wrong can there? its only a lead going to a bulb? or is there anything else involved
cheers

Replace the cord. Then try. Braker after that. Could be old and week. Still doing it try a differnt bulb. after all that it's still doing it something in the ballest is messed up. Get it fixed or replace it. Only reason I say this order is it's cheapest fixes first.

are you running more than 15 amps on 1 circuit?