SDS2202X-E Calibrate signal problems on CH1

[trick2011]

So I bought a SDS2202X-E and as you do you begin toying around with it and checking if it works properly. However I found that I have problems when measuring the calibrate signal with only CH1.

I connect CH1 (x1) on calibrate with the ground diligently connected to the right point and I get the following image for timescales below 2ms:


This is not correct, as the signal is 3.2V 1KHz. I verified this with another working scope.

The funny thing is that when I enable CH2 I get a correct signal:


My settings for CH1 are as follows:



My firmware version of the scope is: 1.1.19 R5


I can't for the life of me figure out what I'm doing wrong. I also couldn't find any prior posts online about this behavior so therefore this post.

[tautech]

Welcome to the forum.

Certainly your first image shows something out of wack so my advice is to hit Default and check the result.
If things are still not right run AutoCal and check again.

BTW, you can grab screenshots to USB with the blue Print button.

[trick2011]

Hi tautech and thanks.

I've tried that but it only results in these situations:

Default


Default + Auto set


Something else that I should have noted: the reference is peak 6.4V on CH1 while it is on CH2 and actually 3V

[tautech]

Further questions:
Did you run Self Cal with all probes disconnected ?
Did you install 1.1.19 R5 or did it come in the scope ?

Probe Compensation output as we know is 1 KHz and ~3Vp-p which with a 500us and 1V/div setting should give an edge every div and ~3 div p-p display. Can you get that with manual settings ?

We can work with probes on 1x settings for now but 10x settings also need to be checked OR swap probes to check there are no problems with a probe.

[trick2011]

Yes I calibrated with probes disconnected.

I upgraded the firmware to install my Logic Analyzer

When I manually set it to those parameters I get multiple situations:

Situation 1, CH1 enabled CH2 disabled, div is 500us:


Situation 2, CH1 enabled CH2 enabled, div is 500us:


Situation 1, CH1 enabled CH2 disabled, div is 2ms:


In the first and last situation CH1 measures 6V (out of vertical range on screen) but in the second situation it measures 3V.

This happens with both 1x and 10x for both the packaged probes.  (I could get another probe from another scope)

[tautech]

I upgraded the firmware to install my Logic Analyzer

Please try installing the 1.1.19 R5 firmware again.
https://int.siglent.com/upload_file/zip/firmware/Oscilloscope/SDS2000X-E_1.1.19R5_EN.zip
Instructions attached.

[trick2011]

No change after update.

I do find the restart instructions odd as it requires a hard shutdown via the power button but no changes.

[tautech]

No change after update.

I do find the restart instructions odd as it requires a hard shutdown via the power button but no changes.

Yes you can hold the power button until it shuts down however I only hold it for the count of 2 then release it and a few seconds later it will shut down. I can't say I've ever noticed any difference and we've done 100's of updates over the years as every unit goes out the door with the latest FW installed.

Have you tried rolling back the firmware to an earlier version to see if the issues remain which if they do will point to a HW failure that you should contact your supplier for a warranty claim.

[trick2011]

With the 1.1.19 R2 version flashed:

Situation 1, CH1 enabled CH2 disabled, div is 500us:
Situation 2, CH1 enabled CH2 enabled, div is 500us:
Situation 1, CH1 enabled CH2 disabled, div is 2ms:

Signal results are the same except for the fact that the 0V level of the signal is raised by 1.3V.
I'm showing situation 1.


====
I Re ran for 19R2 and I must have updated/calibrated wrongly the problem is exactly the same.
====

With the 1.1.17 R6 version flashed:

Situation 1, CH1 enabled CH2 disabled, div is 500us:
= same results
Situation 2, CH1 enabled CH2 enabled, div is 500us:
= same results
Situation 1, CH1 enabled CH2 disabled, div is 2ms:
= same results

[tautech]

trick2011
I sent a link to this thread to Siglent about your scope and they sent me a new firmware version they want you to install.
Pop me a PM with your email and I'll flick it through to you.

[Shock]

Trick2011, be sure to invoice Siglent for the time you spend troubleshooting their products.

Or perhaps you can request a hacker try to fix the Siglent firmware for them, like was done in this thread:
https://www.eevblog.com/forum/testgear/siglent-sdm3045x-enough-is-enough/msg3908264/#msg3908264

[tautech]

Trick2011, be sure to invoice Siglent for the time you spend troubleshooting their products.

Oh FFS Shock. 
Something went wrong with the firmware install or he has a faulty unit.

May I remind you about the level of support you might instead get from an A brand:
https://www.eevblog.com/forum/testgear/keysight-officially-lost-the-plot-dont-buy-if-youre-a-hobbyist/

[trick2011]

So tautech gave me a new version of the firmware (V1.1.20R3) and this one works as it should. So at this time it seems like a software problem instead of a hardware one so that is a relief.