SDS7102 no buttons or trigger working anymore

[tomatos666]

Hello,

I have a problem with my SDS7102.
The buttons and trigger are not working during measurements.
The SDS7102 is still measuring and displaying the data correctly, but I can no longer change any values. I have checked the flat ribbon cable that connects the buttons to the mainboard.
After reassembly, the oscilloscope worked normally for 3 minutes, but then the same problem occurred again.
Has anyone experienced the same issue before and found a solution?
I have tried reaching out to Owon, but unfortunately, they have not responded to my inquiries.

[tomatos666]

Hello,

Unfortunately, no one has reported the same issue.
I have disassembled the oscilloscope again and taken measurements.
The encoders are not switching cleanly in some cases. Some of them remain stuck in the high state. I have attempted to switch all the encoders to low at both the output and input. However, the problem still persists. The oscilloscope remains inoperable. Could attaching capacitors potentially provide a solution?
I also noticed that as soon as the encoders go high, there isn't a clean 3.2V signal present; there are many disturbances. Is it possible that the ICs 74GC4051 and/or 74HC393 are damaged?
The ICs are registering a voltage of 3.2V.

[Whitefoot]

I don't have a clear answer to this. One time I went to use my SDS7102, none of the encoders worked. I shut it off and didn't try it again for about a month. It worked fine and still does. Maybe being off long enough reset something?

[tomatos666]

Hi, thank you for your response.
I don't believe it will start working on its own. I'm unsure about the underlying issue.
I've already added a 100nf capacitor to the encoders, but there's been no change. After that, I've desoldered all diodes on the encoders, but still no improvement.
My next step is to replace the 74HC393D and 74HC4051D components, hoping that this will bring the device back to functionality.
Some one know´s where i become parts for this tyoe of scope?
Owon it self dosnt help!

[tomatos666]

I'm afraid I haven't seen any significant changes.
I haven't received a response from Owon.
The local Owon dealer doesn't feel responsible.
The SDS7102 is being disassembled further and further. Unfortunately, I haven't been able to pinpoint the issue.
Here a video what I have made it that’s show the problem. https://youtu.be/BqU3ueHhXDo

[jmakivir]

Hi,
I have the same problem which appeared after the scope sat unused for a while. I too started by checking that flat flex cable but couldn't find any obvious problems with it.
I also checked the small lithium battery on the main board with a DMM and it was completely drained. I don't know whether or not that battery is used for storing the settings or is it just for the clock, but I'm wondering if it might be possible that this problem is caused by some weird firmware bug related to the scope failing to restore some settings to their defaults. Unfortunately I don't remember my firmware version but the SN / batch number is in the 1203xxx range.
Have you checked the state of that backup battery in your scope?

[Tjuurko]

The battery is used only to power internal clock.

[tomatos666]

Hello,

Thank you for your response. Yes, I've checked the battery, and there are some voltage readings.
I managed to bring the scope back to life by using the USB cable and PC to adjust the settings. After that, the scope worked normally. However, a month later, the same issue has occurred. None of the buttons are functioning anymore.
Now, I have to reinstall the software and drivers because I formatted the PC that I normally use... 
I've checked everything. All the cable connections and signals seem to be okay from what I understand.
I suspect there might be a problem with the firmware, especially when the scope is left unused for an extended period...
This time i let you know what to do to bring back to live...

[tomatos666]

Hello,
I would like to give you an update.
The oscilloscope still doesn't work.
The buttons are not functioning. Furthermore, although the oscilloscope is recognized by the PC, there is no communication between the PC and the oscilloscope.
I have tried to perform an update. However, I always receive a message that the serial number cannot be read...
Does anyone have an idea what else I can do?

[tomatos666]

Hello,
Yesterday, I managed to update the oscilloscope.
I started with H8. Unfortunately, the buttons still didn't work.
So, I decided to try older versions. Lo and behold, with version H2, the buttons worked, and I could access the oscilloscope via USB.
However, the lines from Input 1+2 were missing. 
After 5 minutes, the buttons stopped working again. 
The oscilloscope was also no longer recognized by the PC. I am back to square one...
Could it be that the NAND is defective and losing parts of the program? What else can I do? Does anyone have an idea?"

[tomatos666]

Hello,

I'm not sure if anyone is reading this, but I'll provide an update.
Using JTAG, I managed to read the memory to check if the NAND has many defective blocks.
After several attempts, I succeeded.
I found information on this at the following page:
https://radiokot.ru/forum/viewtopic.php?f=10&t=70052&start=520
The NAND has only one defective block, 0165. As far as I found out, having 1-2 defective blocks in the NAND is not a problem.
Subsequently, I completely erased the NAND and overwrote it with another NAND dump.
I then performed updates and calibration.
The buttons are working again, and the measurements are displayed correctly.
Apparently, the NAND had a faulty program. Whether it was just a random error or indicates an impending defect, I cannot say. At the moment, the oscilloscope is functioning.
How long it will continue working is another matter.
If the problems occur again, I will replace the NAND.

[tomatos666]

Hi,
I have the same problem which appeared after the scope sat unused for a while. I too started by checking that flat flex cable but couldn't find any obvious problems with it.
I also checked the small lithium battery on the main board with a DMM and it was completely drained. I don't know whether or not that battery is used for storing the settings or is it just for the clock, but I'm wondering if it might be possible that this problem is caused by some weird firmware bug related to the scope failing to restore some settings to their defaults. Unfortunately I don't remember my firmware version but the SN / batch number is in the 1203xxx range.
Have you checked the state of that backup battery in your scope?

Hello jmakivir

After all attempts were unsuccessful, I noticed something yesterday. The oscilloscope started working. The battery voltage was 2.65V, but then suddenly the battery voltage dropped and the buttons stopped working. I tried charging the battery with a power supply. However, only the CPU became lukewarm, and the battery voltage dropped completely to 0.

I believe the CPU has a defect. I can't say exactly what the problem is, but I can say that the malfunction of the buttons is clearly related to the discharge of the battery.

Perhaps someone has an idea. The CPU likely cannot be easily replaced.

[tomatos666]

Update:
I have now replaced the CPU, but unfortunately, it didn't resolve the issue.
The problem persists, and none of the buttons or switches are working.
Additionally, the oscilloscope is not being recognized by the PC via USB.
There must be a connection between these issues.