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What is wrong with my oscilloscope?

  1. Jan 22, 2016 #1
    I have been fighting it for days and no matter what I try I can't make the waves bigger. The signal I'm putting in is a 1 volt peak to peak wave and if I adjust the voltage on the scale to 1 volt I can't see the wave and if it set it to 10mv I can see it but barley. I have tested the voltage with a meter and it's 1 volt and if I try to use this scope to tune a amplifier the wave is still tiny like on the picture. How can I fix this?
  2. jcsd
  3. Jan 23, 2016 #2


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    Have you tried another probe?
  4. Jan 23, 2016 #3


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    If not a probe fault....
    Perhaps you have the time base too fast. Eg transitions are off the screen left an right so it looks like a DC signal and any signal you see on the 10mv setting is actually noise?
  5. Jan 23, 2016 #4


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    If not the above, check that you're not triggering on noise, and that your trigger conditions are appropriate for your signal.
  6. Jan 23, 2016 #5


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    is the scope probe switched to x10 instead of x1 ??

    what if you connect the probe to the scopes calibration point on the front panel ?
    they are usually a 1V p-p square wave

    Are you REALLY SURE you input voltage to the scope from your project is 1V p-p ???
    have you proved that using some other method ?

  7. Jan 23, 2016 #6


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    Do you have two channels on the scope and do they exhibit the same fault? Is there a calib output on the scope?
    Are all the timebase, trigger, gain and signal selection settings correct. What happens with 1.5V DC from a battery (the easiest calibration source) of other sources.
    What sort of scope is it? Analogue / digital / PC based etc. IS there a make and model number available?
  8. Jan 23, 2016 #7
    Oscilloscopes can be a pain to troubleshoot. There are so many simple mistakes that can mess with a clean signal. The other posters mentioned some of the common ones.

    First I would find a basic "How to use" video on youtube. Perhaps you can find one specific to your scope? It should walk you through most of the controls. As davenn said, there's usually a clean signal on the front that gives a 1V square wave to practice with. Once you get that going it should be easier to track down a good signal.

    Play around some. There are always quirks or unexpected limits, so take the time to learn. It will pay off in the long run.

    Good luck.
  9. Jan 23, 2016 #8


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    agreed :smile:

    am strongly suspecting user error rather than faulty scope
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