I recently contacted you about a speaker problem,however after further research I discovered a fuse had blown inside the amplifier.Originally this Fisher amplifier CA-880 was operating with one channel.The meter level indicated the second source output working.I thought it was the speaker only.So, I ordered the fuse for the inside section of the amplifier,I removed the housing,inserted the new fuse,replaced the housing.But,when I lifted the unit I heard a sound like something had dislodged.I connected the unit,now I have no power ar all.What happened? The amplifier was operating even with the blown fuse inside.Now it's dead!!! Please help me determine how opening the housing to replace a fuse could have caused a complete shut-down of the power source.