Troubleshooting; General Problems; Nothing Happens At Turn-On; Reset Procedure - Protek 9216A User Manual

Chapter
5

Troubleshooting

Hints for Solving Problems
In this chapter, suggestions are given for solving common troubleshooting problems

General Problems

Nothing Happens at Turn-on

Make sure that the power entry module on the rear panel is set for the AC line voltage for
your region, that the correct fuse is installed, and that the line cord is inserted all the way
into the power entry module. The selected line voltage may be seen through the clear
window, just below the fuse.
When the unit is plugged in and turned "ON", the unit's program version number and
model name will be briefly displayed. Then the self-tests should execute.

Reset Procedure

If the unit displays no sensible message, the "cold boot" procedure may fix the problem.
To reset the instrument, turn the unit off. Then, while holding the backspace key ([]),
turn the unit "ON". This procedure initializes the RAM and recalls the factory calibration
and default values. The default parameter values and instrument settings are listed in
Volume 1 of this manual.
Internal Fuse Check
If the unit powers on correctly but makes unstable or wildly inaccurate readings, the inter-
nal fuse may be blown. This can also cause the unit to fail the self-test (Out Err3). To
change this fuse, the top of the unit must be removed. To do this, first turn off and unplug
the unit. Next remove the four screws located on the bottom at the comers of the unit.
Place the unit right side up on its feet and gently slide the plastic top off the metal base.
It is necessary to slide the top gradually off the fixture and the back panel, since it fits
tightly over these. When the top is removed, stand it on its left side near the unit to avoid
damaging the front panel cables. The internal fuse is located near the fixture, on the right
hand side of the unit. Remove the old fuse and inspect it for damage. If it is damaged,
replace it with a 250V, F250mA fuse. Replace the top, taking care to align it over the fix-
ture and rear panel. Finally, replace the four screws and verify that this fixed the unit.

External Bias Fuse Check

If the unit makes unstable or wildly inaccurate reading when an external bias is applied,
the external bias fuse may be blown. To change it, power off and unplug the unit. Use a
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