Trouble Shooting a Player Piano can be intimidating if you don't have a thorough understanding of a few basic principals. One of the most important of these principles is 'How a Valve Works' -click here. Next is understanding the primary function of each of the major components in the system -click here. Next is isolating the component that is most likely causing the problem, and testing that device -click here. From that point, it's best to get the service manual (if one is available) -click here for your particular player mechanism. While all player pianos operate on exactly the same principles, pictures and diagrams are often helpful. For general information about 'the basics' and Rebuilding a Player Piano -click here.

As the player piano developed, a number of highly sophisticated systems were manufactured. They include the Duo-Art, Ampico, and Welte-Mignon Reproducing systems. Slightly less complex are 'Expression Systems' like the Recordo, Art Apollo, and Angelus. However, while these systems are indeed quite complicated overall, every one of the devices in the mechanism use the same principles of operation as every other type of player piano. In a very real sense, player pianos are like the automobile before computers came along. While valve trains, carburetors, and ignition systems were designed differently, they all operated on the same principles. That said, it is still highly recommended that you purchase the appropriate manual for any reproducing or expression system before attempting to do any trouble shooting.

In order to do effective trouble shooting, you need a source of vacuum. A regular household vacuum cleaner produces more than enough vacuum to trouble shoot virtually any device in any type of player piano. In fact, most vacuum cleaners produce too much vacuum, and for that reason it is wise to have a means of regulating the amount of vacuum. This can be accomplished in either of two basic ways. One is by introducing a controllable leak into the vacuum supply line. Although crude, this can be done by putting a "T" into the supply line and connecting a faucet to one leg of the "T". The second way is by varying the voltage to the vacuum cleaner. This can be easily accomplished by putting a household dimmer switch in series with one leg of the A/C line. (Naturally, once you have a variable vacuum source, you'll need a number of different sized fittings to connect the source to the device being tested.)