I just went through four of my foot pedals and each one works when the effect is engaged. But when the footswitch is clicked... silence. I can't believe all three miraculously have this exact same problem at once. I am using a wall adapter rated at 9.6 volts DC, an older cable connected to the input, and a short cable for the output. Like I said, the sound and effect worked when the effect is engaged, but when the effect is turned off, there is no guitar.
What is the solution to this problem?