Rigol DS1052E Oscilloscope acting wierd.

[LarsHansen]

Hi All you clever guys :-)

Im rather new to electronics, and Im really in trouble here.

Im have a bit of a puzzle here, regarding my Rigol DS1052E Oscilloscope.
Im trying to adjust the probes but get a wierd result on ch 1.
For both channels I use the same settings:
Coupling = DC
Bandwith limit = on
Probe = 10x (Also 10x on the actual probe)
Digital filter = OFF.

I use the squarewave on the scope as input for both channels, and I use the same (one) probe for both channels.
Channel 2 gives me the expected squarewave with 3 volt signal.
Channel 1 however gives me 1/5 = 600 mV and the signal is noway near a squarewave. Se attached photos.

Please give me your advice.
If I can assist you with further information, then please feel free to comment regarding this.

Thanks in advance.

[Performa01]

For both channels I use the same settings:
Coupling = DC
Bandwith limit = on
Probe = 10x (Also 10x on the actual probe)
Digital filter = OFF.

For probe calibration, bandwidth limit should be OFF in general. But then again, the BW limit cannot explain the odd effects shown here.
You haven't set both channels identical, at least there is no bandwidth limit on channel 2.
Don't know about the digital filter - make absolutely sure it's really OFF, because it's about the only setting I can think of which could cause such funny results.

I use the squarewave on the scope as input for both channels, and I use the same (one) probe for both channels.
Channel 2 gives me the expected squarewave with 3 volt signal.
Channel 1 however gives me 1/5 = 600 mV and the signal is noway near a squarewave. Se attached photos.

Sorry, but I see something different.
You get a clean squarewave 0 to 300mV (=300mVpp) on channel 2.
On channel 1, there is a triangular waveform 128 ~ 680mV (~550mVpp), which might be a hint on a bandwidth limit set very low (digital filter?)

If the settings are correct and the weird behavior persists, I would suspect something's wrong with the Ch. 1 input.

If it's the usual split path amplifier configuration, it looks like only the DC path (with an OpAmp) is working, whereas the HF amplifier is dead. Maybe a capacitor has failed (unlikely, more likely would be a bad solder joint) or a transistor or two have died and need to be replaced...

[tautech]

Sanity check first.....
Select scope Defaults.
Now use Autoset.

Still have weird result ?
If so the input is likely damaged, possibly from an overvoltage event.
I'm sure there is a thread somewhere here where these scopes have been reverse engineered and the schematic should be listed along with component values.

Hopefully someone will provide the link.

[Gary350z]

I have one of these scopes.

First thing, set scope to defaults.

The probes on these scopes are known to have problems:
1. The X1/X10 switch can be intermittent.
2. There can be a bad connection between the probe tip and the hook tip adaptor.

Wiggle the X1/X10 switch while watching the screen.
Wiggle and rotate the hook tip adaptor while watching the screen.
Swap the probes between channel 1 and 2.

Does channel 1 still have the problem?

[LarsHansen]

Yes channel 1 still has the problem. Apparently its broken.

[rstofer]

I assume you have swapped the probes from channel to channel?

[LarsHansen]

Yes exactly. But thanks :-)

[JFJ]

The channel 1 trace looks like what you might expect if its ground connection had failed (the solder joint to its BNC connector ground pins may have cracked).

A simple check would be to measure the resistance between the outer shells of the channel 1 and 2 BNC connectors. Alternatively, you could just short the connectors together, with some thin bare wire, refit the probe to channel 1 and repeat your probe compensation test.

An even simpler check would be to connect your probe's ground connector clip to the ground terminal on the front of your oscilloscope.