To add to the rest of the comments, I've repaired a number of keyboards to include several Matrix 6 and 6Rs and many more Korg and Roland keyboards. I did recently pick up an old Korg DW-8000 that had obviously been in a flood and given the locale of the shipper I could only assume it was water damaged from hurricane Sandy. It was sold as 'For parts not working' and after receiving it and opening it up I realized what had happened to it. Surprisingly after disassembling the instrument and cleaning out all the sediment, and putting it back together only then did realize everything had survived. I sprayed the circuit boards with battery terminal cleaner that you can buy at most auto parts stores, let them soak in it and then just rinsed them off with water. The battery terminal cleaner really seemed to dissolve much of the grit, grime and surface corrosion that had started to show on the IC pins. The biggest threat to a circuit board when exposed to moisture are short circuits that burn up ICs, transistors and whatever else it can find ultimately gets exposed to too much current it there is any power to them. As long as no power was applied your only next worry would be the memory battery however it may not be able to deliver enough current in a short circuit to cause any damage. In a high moisture environment static electricity and discharge potential can be quite low. My personal best recommendation: Clean them up with a solvent that won't attack the circuit board or components, let them dry thoroughly, maybe even for a good week or two depending the average humidity of where you're located, then make sure all the terminal contacts are clean, nothings shorted on the circuit boards and put everything together and see what happens. Then troubleshoot from there...

--- In oberheim@yahoogroups.com , "albertadentist" <trey.petty@...> wrote:
>
> Hey All,
>
> I have / had a Matrix 6R, Matrix M-1000 and Expandar XK keyboard, along with other panels and boards, all analogue, all working in great shape.
>
> Calgary, Canada had a massive flood last Thursday, and all of my equipment was completely underwater for three days. The water slowly settled, leaving silt and mud everywhere.
>
> Yesterday, I pulled it all out of the water-soaked basement, and set it out.
> Everything is coated in layers of mud and silt, not to mention being submerged in water for 3days.
>
> Is anything salvageable
> Or, is it all toast
>
> And, I won't even get into my 3600 record vinyl collection...
>
> Heartbroken,
> Trey
>