Feedback Array is resolved only when you become the active ship during the Combat phase. If a ship equipped with Feedback Array destroys an enemy ship of equal pilot skill that has not attacked yet, that ship is not removed, following the simultaneous attack rule. (X-Wing FAQ, Version 4.2.1, Updated 07/01/2016)
Using Feedback Array does not count as an attack, and can be used against touching ships and while a ship has a Blinded Pilot Damage card (original Damage deck) assigned to it. Feedback Array cannot be used while a ship is overlapping an asteroid or has either a weapons disabled or cloak token, or has the Blinded Pilot card from The Force Awakens Core Set damage deck.
When using Feedback Array, during the Combat phase, you cannot have performed any attacks this phase before you became the active ship and cannot perform any attacks this phase after you became the active ship. (X-Wing FAQ, Version 4.2.1, Updated 07/01/2016)
A ship equipped with Feedback Array can use this ability only if it has at least 1 hull remaining. (X-Wing FAQ, Version 4.2.1, Updated 07/01/2016)
If you have multiple copies of Feedback Array equipped, you can use only 1 Feedback Array during the Combat phase. (X-Wing FAQ, Version 4.2.2, Updated 10/17/2016)