I recently got a Rigol DS1054Z, am new to oscilloscopes (have only had it for a few weeks), and suspect one of the probes might be bad. (The Rigol shipped with PVP2150 probes.)
When measuring a slowly charging capacitor as it neared full charge, the trace would inexplicably "drop out" (showing a noisy reduced voltage around 90% of the actual voltage) but then return to tracing the exponential curve.
In troubleshooting this by swapping out probes, using different channels, etc., I've isolated it to an apparent bad connection in the probe that I have been primarily using (associated with channel 1), with the noise being exacerbated if you handle the probe, and in particular, if you gently rotate the jacket between where the probe connects to the wire (see the attached picture).
To further ensure that this has nothing to do with my capacitor breadboard setup, I was able to reproduce the issue by rotating the jacked when the probe is connected to the test compensation square wave on the scope. This doesn't happen with any of the other probes.
Attached are pictures showing the noise when measuring the capacitor, showing no noise for the other probes (I rotated the jackets on all of them). Also shown is the noise when connected to the compensation test signal, along with a picture of the jacket I'm referring to.
The questions I have are:
Is this normal? In other words, did this probe just go bad because I was using it the most frequently?
If not, is there some way I can disassemble the probe to fix the apparent bad connection? (It seems that with rotating the jacket, the noise has subsided somewhat, so I'm assuming there is just a bad connection in the probe.)
I'm also wondering if these probes are just low quality, prone to going bad, and I should purchase a better set, or whether I just happened to be unlucky in getting a bad probe and I should follow up with the reseller.