Your Prophet '08 shouldn't require much in the way of special care to keep it running, but a good cleaning from time to time will keep it looking and behaving like new.
Cleaning the Metal and Overlay
Isopropyl alcohol is recommended for cleaning the metal surfaces and the Lexan overlay. It will remove finger oils and any dirt and grime that builds up on the surface over time. You should be able to buy isopropyl "rubbing" alcohol at any pharmacy. Just apply a small amount to a soft cloth and gently wipe the surface. Soft cotton or microfiber cleaning cloths work great.
Cleaning and Maintaining the Wood Panels
The wood—African mahogany or bubinga—is oil finished. It is not stained or finished in any other way. The wood may dry out over time, especially if it is exposed regularly to sunlight. The best way to clean and treat the wood is with tung oil. Follow the instructions on the can of oil for best results. We can offer a couple of tips, though. It's better to apply the oil sparingly. If you apply too much and leave it until it thickens, it can be difficult to wipe off. The wood may also get shinier the more oil you apply, which you may or may not want.
Treating the Non-Detented Encoders
If the non-detented encoders become oxidized, they can skip values or behave erratically. The best way to treat the encoders is to remove the panel board and apply a product called Deoxit directly to the encoder housing. Some customers have reported successfully treating the encoders by applying Deoxit to the encoder shafts without removing the board, but we don't recommend it.
We use both the 5% and 100% solutions of Deoxit. If you are only using one, we recommend the 100%. It is easiest to apply using the needle dispenser bottles. The tubes also work well. The sprays are not particularly well suited to this application.
Opening the Prophet '08 Module
Place some padding (for example, a towel, blanket, or bubblewrap) directly behind your Prophet. Remove the knobs. They fit tightly, but just slide on and off. Remove the four screws from the front panel, the five screws across the back, and the five screws along the bottom, front edge. It is not necessary to remove the wood end panels. Lift the rear edge of the top panel until it clears the bottom panel, slide it forward slightly so the bottom flange is free of the circuit board, and lift up. Lay the top panel face down on the padding.
Note: If the rack ears are on and have been mounted using the incorrect screws (the longer ones used for the wood panels), the screws may prevent the top panel from being removed easily. If that seems to be happening, remove the rack ears before removing the top panel.
Removing the Panel Board
There is a ribbon cable that connects the main board to the front panel board. Disconnect it from the panel board. Remove the board screws. You can now lift out the panel board.
Applying the Deoxit
The encoders have three leads. On the side opposite the leads, there is a narrow crack between the encoder's metal top and the plastic housing. That is where you will apply the Deoxit. Lean the board against something so that it is nearly vertical, with the encoder leads facing down.
If you are using both the 5% and 100% solutions, start with the 5%. (The 5% is thinner and, therefore, application is a little easier. And it makes the 100% go in easier, as well.) Apply a drop of Deoxit directly to the crack on an encoder. The first drop takes a little longer to work its way in, but it gets easier with successive drops. Turn the encoder shaft between drops to distribute the Deoxit inside the encoder. Apply two or three drops of the 5% and then two drops of the 100%. If you are using just the 100%, apply three drops. Wipe off any excess.
After treating the encoders, lay the board flat and give the encoders a turn.
One treatment is typically enough to get the encoders working like new, but particularly stubborn encoders sometimes require a second application. Also, it may help to let the board sit overnight before use.