(a) Disconnect the chair power cord from the building power supply.
(b) Remove the chair plastic cover by removing the staples securing
the tails of the cover to the underside of the wood seat frame. Slip cover off of the chair.
Remove the 11 Phillips head screws attaching the toe board cover
to the chair.
(d) If not secure, make a secure connection of each cord.
(e) If that's not the problem, continue to the next probable cause.
There is a faulty solid state automatic control board. Test by using a
(a) Check receptacles on the chair junction box for a reading of 115v or
220v, as applicable.
(b) If there is a reading, the automatic control board is faulty.
(c) Remove and replace the automatic control board. Refer to Lesson
3, Remove and Replace or Repair Defective Components of the Dental Chair.
There is a loose connection in the lift electrical junction box.
(a) Disconnect the chair power cord from the connector at front of lift.
(b) Check terminal 1 (lift connector) for a reading of 115v or 220v, as
(c) If there is no reading, remove the lift motor cover and check for a
loose connection in the lift electrical junction box.
(d) If you find a loose connection, the correct action is to make a
(9) If none of the aforementioned tests proved a probable cause as the
reason for the malfunction you continue down the list of probable causes, using the
testing procedures and corrective actions shown in the troubleshooting guide. The
remaining probable causes are as follows.
(a) A faulty wiring harness.
(b) The manual switches are faulty.