
P
AGE
56
Trouble-shooting and Diagnostics 5.4
This section consists of two columns. The first column is a list of some possible instrument
conditions. The second column is a list of steps that should improve the condition. The steps
should be performed in order until the condition improves or all the steps have been com-
pleted. If the instrument condition has not improved, contact the nearest representative or
factory for assistance.
Trouble-shooting should be performed by qualified personnel using the proper equipment
and following all safety precautions. Whenever possible, the trouble-shooting should be
accomplished with the electrical power disconnected. The instrument contains static sensitive
components so care should be taken to observe anti-static procedures.
Condition
Correction Steps
Display is blank
1. Verify that the correct instrument power, as indicated
on the wiring label on the housing, is supplied to
terminals A & B. If the voltage is not correct, check
the power source.
2. Turn off the instrument power. Wait about 5 seconds
then turn the power on again.
3. Turn off the instrument power, loosen the front panel
screw and remove the instrument from the housing.
Inspect the instrument for poor connections.
a. The white ribbon cable that connects the
Processor board (Appendix A-2, page 64) to
the Power Supply Board (Appendix A-1, page
63), must be properly aligned and seated.
b. The Front Display board pins should be
properly aligned and seated in the sockets on
the Processor board (Appendix A-2, page
64) and the Power Supply board (Appendix
A-1, page 63).
c. The EPROM and RAM chips, located on the
Processor board (Appendix A-2, page 64)
must be free from corrosion and firmly seated
in the socket. Also check the Display Driver
chip U1 loacted on the display board for the
same. Reinsert the instrument in the
housing, tighten the panel screw, and turn
on the power.
4. Turn off the instrument power. Press and hold the UP
and DOWN keys. Turn on the power. Hold the keys
depressed for about 10 seconds. If the display lights
the model number, Program , Tune and Profile mode
parameters will need to be re-entered (pages 25 - 35,
or the Software Ref. Sheet, pages 75-77, if already
filled out).
Model Number Displayed
1. Turn off the instrument power, wait 5 seconds then
is incorrect
reapply power. Verify that the number displayed
during the power up sequence is the same as
indicated on the label affixed to the lower front of the
display bezel.