Installation, maintenance, remedial maintenance and repair of amplifiers, audio visual systems, boom boxes, cameras, cassette decks, CD players and recorders, clocks, computer hardware, computer networks, computer systems, computer systems infrastructure, consumer electronics, digital video players and recorders, disk players, DVD players and recorders, fax machines, graphic equalizers, headphones, home theatre systems, intercom systems, keyboards, laptop computers, mini disk players and reco...