Possible Reasons of Common Oscilloscope Problems
Oscilloscope can be used in many fields. When using, you may run into some problems. Here are the possible reasons of some common problems.
1. No spot or wave shape
The power isn’t connected.
The brightness knob isn’t adjusted well.
The shift knob of X or Y axis is at a slanting position.
The balance potentiometer of the Y axis isn’t adjusted properly, which results in a serious imbalance in the DC amplifier.
2. The horizontal waveform can’t be shown.
Trigger selective switch is turned to the outside and no external trigger signal is input, which result in no sawtooth wave (STW).
Level knob doesn’t adjust properly.
The stability potentiometer doesn’t adjust to the critical state that enables the scanning circuit to be triggered.
The X-axis selection is wrongly put in the external position and no external signal is input to the socket.
For two-channel oscilloscope, if only Channel A is used (no input signal in Channel B), and the trigger switch is pulled to the location of YB, there will be no STW.
3. The vertical waveform can’t be shown.
Input DC-coupling ground-AC switch was wrongly put in ground position.
The high and low potential ends of the input are at the anti-termination of that of the circuit.
Input signal is too small and the V/div is wrongly pulled to low sensitivity level.
4. The wave isn’t stable.
The stability potentiometer is over-rotated clockwisely, resulting in scanning circuit under a self-excitation scanning status but not a critical state to be triggered.
Trigger coupling AC, AC (H), DC switches aren’t selected the correct levels according to different signal frequency.
When the high-frequency trigger state is selected, the trigger selector switch is mistakenly placed outside the file.
Some oscilloscope will display instable wave when scanning under the automatic transmission.
5. Vertical lines are too intensive or displayed as a rectangular.
t / div switch isn’t selected properly, resulting in f scan too lower than f Signal.
6. Horizontal lines are too intensive or displayed as a tilt line horizontally.
t / div switch isn’t selected properly, resulting in f scan too higher than f signal.
7. AM waveform disorders.
t/div switch is improperly selected, resulting in incorrect scanning frequency that is selected according to the amplitude selection frequency but not the audio amplitude modulation signal frequency.
As operators may lack knowledge of the principles of oscilloscope and oscilloscope’s control panels, they may encounter many problems when using. Knowing them ahead will be a great help.