Another day where I'm thankful I had a Studio Maintenance class when I went to school. My Sound Devices 744T audio recorder had some buttons that were becoming unreliable. I delicately disassembled it, removed the faceplate, and discovered some grime building up on the switch contacts on both the front control panel circuit board and the contacts on the back of the white rubber buttons. A few Q-tips and a little 99% isopropyl alcohol cleaned them right up and the old girl is back in service and good as new!
Dave Burt is a career audio engineer and is currently working as a freelance Production Sound Mixer.