Tenma 72-2650 Operating Manual page 58

Troubleshooting :
1. After pressing the power button of the DSO, the
screen is dark and will not display:
①. Check if the power connector is properly connected
to power socket
②. Check if the power button is pressed to the ON
position.
③. Restart the instrument after completing the above
checks.
④. If the product still does not work normally, please
contact Tenma.
2. Cannot acquire signal waveform
①.Check if the BNC connector of the probe is properly
connected to DSO
②.Check if the probe is working properly by connecting
the probe to "Probe compensation signal output" and
check for any signal waveform;
③. Check if the probe is properly connected to the device
under test.
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72-2650/72-10510/72-8225A /72-8705A/72-8710A user manual
④. Try to acquire signal again.
3. The voltage amplitude measured is 10 times higher
or lower than the actual value:- Check if the attenuation
coefficient of the channel matches with the attenuation
rate of the probe used.
4. The signal waveform is not stable:
①. Check if the trigger source setting in the trigger menu
is matched with the actual channel input of the signal.
②. Check the trigger type: Most of the signal can be
triggered by edge trigger mode; while video signal can
be triggered by video trigger mode. Only in the correct trigger
mode can the waveform be stably displayed.
③. Change the coupling to "high frequency rejection" or
"low frequency rejection" display to filter out the high
frequency or low frequency noise that maybe interfering
with the trigger.
5. No waveform display after pressing RUN/STOP key
①. Check if the trigger level exceeds the waveform range
and the trigger mode is "Normal" or "Single", if yes,