Recommendedtest Equipment; Self Diagnosticprogram; Recommended Troubleshooting Equipment - Keithley 595 Instruction Manual

Table 8-8. Recommended Troubleshooting Equipment
Equipment 1 Use
I
DMM with O.Ol5% basic DC accuracy,
1OMO input impedance (Keithley
Power supply and DC voltage
Model 197 or equivalent).
checks; analog signal tracing;
continuity; static logic levels.
Storage oscilloscope, DC-50MHz
bandwidth.
Digital and analog waveform
checks.
8.8.1 Recommended Test Equipment
8.8.3 Self Diagnostic Program
Success in troubleshooting complex equipment lie the
Model 595 depends not only on the skiU of the technician,
The self diagnostic program can be used to test~the front?
panel indicator lights, access the software revision level, and
but also relies on the use of accurate, reliable test equip-
ment. Table 8-6 lists the miniium recommended equip-
enter a special mode to allow signal tracing through the
ment for troubleshooting the the Model 595. Other equip-
instrument. Enter the diagnostic program as follows:
ment such as logic analyzers and capacitance meters could 1. Turn off the instrument for &least three seconds if it
also be helpful, especially in difficult situations. is presently turned on.
2. Press and hold the UC, button while turning on power.
8.8.2 Power Up Self Test
3. The instrument will test RAM and ROM as it normally
does on power-up, and then turn on all front panel in-
dicator liihts andhisplay segments. The instr&nent will
Upon power up, the Model 595 will automatically test its
RAM and ROM memory, and check for proper calibration
fenwin in this configuration as long as the C/Co button
1s held in.
constants. If a RAM error occurs, the following message 4. The software revision level will be displayed when the
will remain on the display:
C/C, button is released. A typical example is:
r.r.
Al
If a ROM error occurs, the following message will remain
on the display:
N&e that the revision level of your instrument may be
different.
LO.
5. At this point7 the instrument will enter the diagnostic
mode that switches the instrument among the zero (com-
mon), calibration Ireference). and sienal phases of its
With either error, the instrument will be completely in-
operative. If any of these errors occur, it should be assum-
ed that a problem exists within the instrument. The pro-
blem should be rectified before using the instrument.
mea&rement cycle: The unit '& be @led t&roggh these
phases by repeatedly pressing the C/Co button. The
decimal point wi!.l indicate the range. During the zero
(common) phase, the display will appear as follows:
r=o
If a calibration error occurs, the two exponent decimal
points will flash. The instrument will be functional under
~~6. D
these conditions, but calibration is not accurate. Use the
wing the calibration (reference) phase, the display will
show:
calibration procedures in paragraph S-5 of this section top
calibrate the instrument. Note that this error may also in-
dicate a defective NVRAM (permanent memory).
P=C
8-W