Originally Posted by
mmc8180
You indicated one channel is out - what does that mean? Are you sure it's only one channel or both? Reduced output or completely out? Did you actually confirm they are fried by sending known good signals through known good wiring to them? Did you check that the upstream devices and wiring are sending good signals to the amplifiers by feeding their outputs to known good functioning amplifier channels, and downstream wiring and speakers? Did you switch wiring to channels at various points to see if the problem moves with the wiring change or stays in the same channel? As far as tools needed for this level of diagnosing, get a multi test meter (probably $40 at Lowes) to check for consistent continuity through all your wires. Check both the low-level input wiring as well as the speaker wiring, also visually look for frayed wires, insulation, bad connectors. Do you have the same size speaker wiring for each channel? Is it about 12 gauge wire? Use that same meter to measure the impedances of each individual driver, if possible, to see if it is within spec.