Keysight Technologies InfiniVision 6000L Series, Service Manual

Page: 57 / 100

Troubleshooting
4
6000L Series Oscilloscopes Service Guide 57
If the trace display is unusual or unexpected
✔
Check that the horizontal sweep speed control setting is correct for the
expected frequency range of the input signals.
✔
The sampling speed of the oscilloscope depends on the time/division setting. It
may be that when time/division is set to slower speeds, the oscilloscope is
sampling too slowly to capture all of the transitions on the waveform. Use peak
detect mode.
✔
Check that all oscilloscope probes are connected to the correct signals in the
circuit under test.
✔
Ensure that the probe’s ground lead is securely connected to a ground point in
the circuit under test. For high-speed measurements, each probe’s individual
ground lead should also be connected to a ground point closest to the signal
point in the circuit under test.
✔
Check that the trigger setup is correct.
✔
A correct trigger setup is the most important factor in helping you capture the
data you desire. See the User’s Guide for information about triggering.
✔
Check that infinite persistence in the Display menu is turned off, then press the
Clear Display
softkey.
✔
Press the
AutoScale
key.
If you cannot see a channel
✔
Recall the default setup by pressing
Save/Recall
then
Default Setup
. This will
ensure that the trigger mode is Auto.
✔
Check that the oscilloscope probe’s BNC connector is securely attached to the
oscilloscope’s input connector.
✔
Check that the probe clips are securely connected to points in the circuit under
test.
✔
Check that the circuit under test is powered on.
You may have pressed the
AutoScale
key before an input signal was available.
Performing the checks listed here ensures that the signals from the circuit
under test will be seen by the oscilloscope. Perform the remaining checks in
this topic to make sure the oscilloscope channels are on, and to obtain an
automatic setup.