Oscilloscope always showing Sine Wave

[electronicsLearner77]

I have a real problem with my scope for any signal i connect it only shows sine wave, even if i connect with some DC source of 12V it only shows sine wave, not sure why. I tried all the methods but of no use.

 

[crutschow]

How do you expect us to know what is wrong, when you give us no info on the oscilloscope you have?

 

[Externet]

Did it ever work correct before ?
Remove the probe, short circuit its input jack and come back.

 

[bertus]

Hello,

Perhaps the attached PDF will give you some guidelines for the use of an oscilloscope.

Bertus

 

[electronicsLearner77]

The oscilloscope is Keysight DSOX1204A, yes it worked fine for quite several months.

 

[electronicsLearner77]

Did it ever work correct before ?
Remove the probe, short circuit its input jack and come back.

What does short circuit its input jack mean? How to do it?

 

[danadak]

No probe connected, short the bnc center pin (female) to its shell,
eg no input signal is result. Channel 1, all other channels off. Do you
then still get a sinewave ?

Does that scope allow, with a setting, to intertnally route the internal
Wavegen directly to a channel ? That could be the source of the sine...


Regards, Dana.

 

[Alec_t]

Does pressing the 'Waveform generator' key remove/affect the sine display?

 

[AnalogKid]

If the sine wave always is the same frequency, like 50 or 60 Hz, check the ground clip on the probe. If the ground is floating, the scope will pick up ambient power line energy like a radio.

Scope trace photo - ???

ak

 

[electronicsLearner77]

Yes it is around 50Hz, the input is 12V dc, i shorted the bnc but with power off, do i need to power on the oscilloscope will it damage the scope?

 

[Harald Kapp]

do i need to power on the oscilloscope

Of course. How else will you get a display?

will it damage the scope?

No.

 

[danadak]

The scope bnc is an input to a attenuator and a amplifier, so yes
you can short just the bnc, scope connected to nothing else, but
its AC input power, to check noise thru that channel. Note if that
scope is relatively new you need to set the vertical input channel to
DC so that scope can present input path signal from BNC thru all
its signal path.

Regards, Dana.

 

[Hermano]

Usually when you see 50Hz even when looking at DC signals, that means your Ground of the probe is not connected. Check or replace your probe. The Ground wire (with the alligator clip) sometimes breaks under insulation or spring clip becomes weak (the one that attaches it to the actual probe) - in this case it feels loose.