My sound just went out in my car. It has an built in amp. In the trunk

GM CD player mechanisms of that time period beginning in the mid '90s had a 100 percent failure rate. If the radio still has sound and only the CD player doesn't, replace the radio. Since the '94 model year, General Motors will not let us buy radio service manuals or parts. They want all the repair work for their grossly over-priced repair centers. If the radio is also dead, the problem could be in the radio, the amp, the power source to the amp, (blown fuse), or a dead memory circuit to the radio. If the memory circuit is dead, the clock will go back to 10:00 each time the ignition switch is turned on and it won't hold your station presets in memory.