I have been asked, "is it possible to recover all or some of the sound and video equipment lost in the flood waters that Hurricanes Katrina, Rita, and Wilma have brought?" The answer to that question is maybe, but most likely, not.
It's a serious situation just when somebody spills bottled water on your front of house console, but when your amp rack has been sitting under muddy sludge for 2 weeks and then dried, that something completely different. As a rule of thumb: if the water came from above as in rain water, you might be able to recover or repair the unit, but if the water came from below, i.e., flood water, it is very unlikely that you will be able to recover or repair the unit.
In fact, I would not even trust water from above. That "rain" water still had to travel through roofing material, insulation, ceiling tiles or sheet rock. The amounts of contaminants that can be in the "rain" water can be quite high. Water from "below" contains dirt, acids, salts, oils, and other contaminants that are corrosive to electronic components. No amount of cleaning will remedy this.
These precautions also pertain to mic cables, snakes, speaker cables, microphones, instruments, etc.
Also, there are many components that make up an amp or mixer that contain different types of insolation papers, such as capacitors and transformers that just cannot be repaired and is not practical to replace.
My recommendation is to wait to see what your insurance company will do. If there is any question about replacement (the isurance company wants to get the device repaired), then you should contact a qualified technician or third party system integrator/vendor for an opinion.
A big word of caution, though. Do not turn on any equipment that has been flooded or is suspicious until you have it checked out but an electrician or qualified technician. You can be electrocuted through the metal case of a component if there is water still in the component.
Now if your gear was not under water or "rained" on, you still may have problems. I had a problem the past few services where the left channel of our playback computer system kept cutting out. I noticed that it was more prevelant during low volume passages. And if the FOH engineer bumped the console there was pop and the left channel went completely out.
One of the yearly maintenance tasks that a sound engineer undertake is cleaning all of the contact points in the system. XLR mic connections on the console, 1/4" inserts, pach bays, etc. If your building suffered some water damage you may need to speed up this maintenance task. That is what I just started. Using a comon deoxidation compound such as DeOxit will not only clean the connections but also dress provide a very good connection when you reconnect the cable. A word of advice, though, use only foam cleaning pads as the cotton one will leave cotton strands in the connectors.
Here is a good source of issues related to cleaning electronic components:
