REMOVE AND REPLACE OR REPAIR DEFECTIVE COMPONENTS OF
THE DENTAL CHAIR
After you have isolated a malfunction you must remove and replace or repair the
component that is malfunctioning. The components covered in this lesson represent
only a portion of the total number of components that could malfunction. However, the
skills required to correct the malfunctioning components are transferable to correcting
all malfunctioning components. You need a medical equipment repairer's tool kit
including at least the following equipment.
a. 7/16 inch open-end or box wrench.
b. 5/16 inch Allen wrench.
c. Phillips screwdriver.
d. Flat-tipped screwdriver.
e. 3/8 inch wrench.
f. 3/4 inch open-end wrench.
REPLACING A FAULTY MANUAL CONTROL SWITCH
The dental chair does not function properly. You have isolated a malfunction to a
faulty manual control switch, for example, manual control switch for chair back (one each for the
doctor's and assistant's controls), manual control switch for chair seat (one each for the
doctor's and assistant's controls), and a manual control switch for lift (the assistant's
bottom switch). After testing per the Dental Chair Troubleshooting Guide, you have no
readings. Therefore, the corrective action you must take is to remove and replace the
switch assembly. Refer to figure 3-1.
a. Disconnect the external power source.
b. Remove the two screws that secure the malfunctioning switch bezel to the