hi one of my speakers has stopped working. the amps are working on both channels. have tried other amps and still same result . i can see no damage to the speaker ie cones etc . my son said he did play his music at high levels. just need some advice what to look for when i decide to take it apart for repair or new parts . many thanks
It's not typical for both drivers to completely stop working unless they have been severely abused for quite some time period.
Before you take the speakers apart - and there's really no need to do that since there's nothing you can repair inside the cabinet - disconnect the speakers from the amplifier and push gently on the woofer. If it refuses to move inward, then the driver is blown and the voice coil is fried. At that point, it need to go into service for repairs.
If the driver moves but doesn't play music, check the system with a battery. Connect a cable to the terminals of the speaker and, at the other end of the cable, connect one (stripped) leg of the cable to a 9VDC battery. While holding the one leg on the battery terminal, flick the other (stripped) leg across the remaining terminal of the battery. The woofer should move in or out depending on the polarity of your battery connection. If nothing moves, the speaker needs to go into the shop for repairs.
If the driver moves when pushed inward but doesn't move when the battery is connected, there might be a blown crossover component. The crossover is mounted inside the cabnet and isn't something you should try to repair yourself. The damaged part should be replaced with the same part by an authorized repair center.
Trying to replace a crossover component yourself could mean you slightly alter the crossover characteristics of the system which would adversely affect the sound quality. Additionally, most drivers are less than cooperative about coming out of the front baffle and you could do some physical damage that would be irrepairable. Let a repair shop do the work.
Speakers normally have a five year warranty and most manufacturers will replace abused drivers once during that time. No guarantees on that last statement but take the speaker to a repair shop anyway.