Keyboard Troubles
Many of the mechanical troubles will be found in the keyboard, such as continuous response or non-response of matrices.
The keylevers sometimes get gummy or sprung to one side and bind on the frame, causing a continuous response of matrices. Another cause for continuous response may often be traced to some foreign substance such as metal shavings or dirt getting between the keylever and the frame.
A large percentage of keyboard troubles can be traced to the keybars. Most continuous response trouble is due to dirty or sticking keybars. These bars have several points of contact with other parts, and frequently a very small particle of dirt or dust will prevent the proper return of the keybar after being raised. This will hold the trigger out from under the cam yoke, which will continue to revolve and cause more than one matrix to drop. This trouble can usually be remedied by blowing out all dust from around the keybars and then washing them with gasoline, using a squirt can or brush to apply the gasoline. Before applying the gasoline, it is best to place a pan or cloth beneath the keybars to catch the surplus gasoline.
Be very careful not to get any gasoline on the cams or rubber rolls, as it will cut the lubrication on the yoke pivot and soften the rubber roll. After washing the bars, blow the surplus gasoline off with an air hose or bellows. Keep the air from the keyboard cams as much as possible, as it has a tendency to dry the oil on the yoke pivot pins, causing slow moving cams.
Sometimes the trouble is above the keybar banking bar. In this case it will be necessary to remove the back cam frame to clean the bars above the banking bar.
Should the keyboard locking bar become loose it may drop down a trifle and, preventing free action of the keybars, make the keyboard touch heavy.
In addition to the continuous response caused by the keylever or keybar, sometimes a dirty and sticking trigger or the trigger hinge rod being bent will cause this trouble. If one of the pins in the stop strip or the cam becomes worn or broken, the cam will continue to revolve.
Some of the common troubles of non-response might be caused by the free end of the cam yoke being dirty or gummy, a rusty, gummy, or bent cam yoke hinge rod, not allowing the cam to drop. A dry cam pivot will often prevent the cam from turning. A hard or oily rubber roll will not cause the cam to turn, especially on a cold morning. A tooth on the stop strip being bent sideways might bind the cam. Something binding the rubber roll, not allowing it to revolve, stops all cam response. A dry cam pivot or a sluggish cam will cause transposition of letters.
To locate the cause of a non-response, first observe if the keyrod is moving. If it is, the trouble will probably be found in the magazine or magazine escapement. If the keyrod does not raise, look for the trouble in the keyboard.
Do not take the keyboard apart every time a few matrices fail to respond correctly. It is much quicker to correct the trouble with the individual parts that may be bothering. Always locate the cause of the trouble before attempting to correct it.