Someone who claims they can fix broken computers, laptops, cars, TVs, microwaves, school buses, VCRs, impacted teeth, gutters, fences, garage doors, plumbing, commercial vehicles, bathtubs, with either using a Estwing Hammer, Chainsaw, Meat Clever, or Jack Hammer while recovering from a bad hangover the night before.
Usually stumbles into work after a 24 hour raided party that caused them to post bail, and just after watching Jerry Springer, and can do so because they are related to the boss.
TV Shows a Hackerjack likes:
McHales Navy, F-Troop, Jerry Springer, WWF, and COPS (see how many friends are on there)
It's a type person who refuses to listen to expert advise or opinions, and claims to be talented enough to be either a brain surgeon, rocket scientist, rock star, president, or WWF wrestler all at the same time - and is never wrong about anything.
A Hackerjack maybe your next car or bus mechanic that works on your vehicle, but isn't qualified, so he hacks away at it.