incompetech
A technician who is unable to solve the problem you are experiencing with a device, and who may, in fact, make it worse.
"Dude! My PCtotally slowed down so I had a guy from The Kwiker Fixers come over, 'n' now it won't even run! Damn! What an incompetech!"
Incompetech
An incompetent technician or repair person: a paid employee whose alleged technical proficiency falls short of solving a problem with an automobile, a computer, a television, or other device, and whose efforts may even make it worse.
"My PC slowed way down, so I called Kwikie Tekkies and the guy they sent was a total incompetech - it runs OK again, but it erased all my tunes! Damn!"