Technical Support Document 025 - 5/97

The TEST MOTORS Diagnostic

When a "Motor Shut Down" message is displayed on the keypad screen, the computer has tried to move one of it's motors, and has failed to acknowledge that motor's movement. There are two tests that will help determine what has exactly occurred to prevent this from happening. The first is the basic Test Motors diagnostic, which tests that the motor drive and motor encoder reading circuitry in the AF Computer Box is working properly. The second is a diagnostic that will test that the system is reading the positional encoders properly. (The positional encoders are used for the accurate measurements needed for Autofocus operation.)

This test will allow the user to run each motor in the Sentinel in a simple "press the arrow and watch the motor move" mode.

During this test, the limit switches are not active, and the mechanical limits of the machine's movement can be overrun, causing damage to the motors, motor pinions, or other components.

1. Turn the Sentinel power on. Immediately after turning the power switch on, press and hold the ENTER key on the keypad. This will disable the Starlite colorhead, as well as tell the Sentinel to skip the Referencing routine.
   
2. After the screen gets to the MANUAL display, activate the Test Motors function in the Diagnostics menu. Press MENU, <8>, ENTER, <3>, ENTER to do this.
   
3. The display on the keypad should appear as shown below:
   

The readouts on the bottom line are the current direction of each motors movement. Both should read "STOP" if no arrow keys are being pressed. If either display is jittering between "STOP," "UP," or "DOWN," that motor's encoder plug is probably disconnected.

4. Move the Lens Motor by pressing either of the Arrow Keys under the numeric keypad. As you press an arrow key, the stage should move, and the direction of movement, UP or DOWN, should be indicated on the keypad's screen:
   

WARNING: In this test, the limit sensors are disabled, and will not protect you from running a stage off the end of the column. Be very careful not to allow the stage to reach the extreme bottom of the column, or to extend the bellows too far (more than 12"). Damage to the Sentinel could result.

5. If the lens stage moves properly, try the neg stage. The operation is the same, but use the arrow keys under the ENTER and CANCEL keys. The readout of the NEG: motor on the keypad's screen should indicate the direction of travel:
   

WARNING: In this test, the limit sensors are disabled, and will not protect you from running a stage off the end of the column. Be very careful not to allow the stage to reach the extreme top of the column, or to extend the bellows too far (more than 12"). Damage to the Sentinel could result.

6. If there are any troubles with the performance of this test, please contact ZBE, with the information you have gained about the nature of the failure, or refer to the table below for information regarding the causes of such trouble:
   

Once you are finished with this test, press CANCEL to return to the Sentinel's main operations screen. Remember, since ENTER was held down during power-up, the machine has not referenced, and therefore will not auto-focus.