Hello guys, after completing the soldering everything works except the V/DIV and SEC/DIV buttons ... what can i check/do about that?
Board Version is 2017 109-1500-00E with newest firmware (62) Obvious soldering points were already post-soldered and the two buttons aren't defective.
Missing button response
Re: Missing button response
Have a look @ schematic: http://www.jyetech.com/Products/LcdScop ... 50main.pdf
You should check voltage at pins 40 and 41 of MCU. It should be ~3.3V when buttons aren't pressed and close to 0V when they're pressed. MCU pins are quite hard to probe so you could check voltages at corresponding resistors R10 or R26 for V/DIV button and R11 or R27 for SEC/DIV button.
Compare results with buttons that work (pins 42, 43 of MCU or R12/R28, R13/R29).
You should check voltage at pins 40 and 41 of MCU. It should be ~3.3V when buttons aren't pressed and close to 0V when they're pressed. MCU pins are quite hard to probe so you could check voltages at corresponding resistors R10 or R26 for V/DIV button and R11 or R27 for SEC/DIV button.
Compare results with buttons that work (pins 42, 43 of MCU or R12/R28, R13/R29).
Re: Missing button response
I had the same problem with the 'OK' button.
Problem is due to very bad soldering by the manufacturer.
I have resoldered the resistor R10-R13 and R26-R28. Only heating, no solderwire.
The schematic http://www.jyetech.com/Products/LcdScop ... 50main.pdf is not correct. SW4 = 'OK ' button.
Problem is due to very bad soldering by the manufacturer.
I have resoldered the resistor R10-R13 and R26-R28. Only heating, no solderwire.
The schematic http://www.jyetech.com/Products/LcdScop ... 50main.pdf is not correct. SW4 = 'OK ' button.
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Re: Missing button response
I originally posted this in the "Tips and Troubleshooting" topic.... But it fits better here...
Everything running EXCEPT...V/DIV not working
Postby albenbrewder » Mon Oct 23, 2017 8:17 pm
Ref: boards: 109-15000-00E (Display); 109-15001-00E (Analog)
Software: 113-15001-064
Initial Display board check showed everything working EXCEPT V/Div push button did nothing.
I have checked all connections and DB4-DB7 appear OK, (Pull downs, V->0 when pressed)
Board soldering appears OK... Problem appears to be either a cpu malfunction or a program bug.
Rest of project was completed and all appears functional EXCEPT I can't change V/Div.
Hardware?
Software?
I agree that the schematic is wrong, SW4 is = 'OK' button.
As suggested, I have retouched the solder points on SMD resistors with no change... Problem still points to a MCU problem, or software problem....
Everything running EXCEPT...V/DIV not working
Postby albenbrewder » Mon Oct 23, 2017 8:17 pm
Ref: boards: 109-15000-00E (Display); 109-15001-00E (Analog)
Software: 113-15001-064
Initial Display board check showed everything working EXCEPT V/Div push button did nothing.
I have checked all connections and DB4-DB7 appear OK, (Pull downs, V->0 when pressed)
Board soldering appears OK... Problem appears to be either a cpu malfunction or a program bug.
Rest of project was completed and all appears functional EXCEPT I can't change V/Div.
Hardware?
Software?
I agree that the schematic is wrong, SW4 is = 'OK' button.
As suggested, I have retouched the solder points on SMD resistors with no change... Problem still points to a MCU problem, or software problem....
Re: Missing button response
Please don't forget to check the buttons themselves. Also check the pull-ups (R26 - R29). Since the same MCU pins (PB4 - PB7) are used to driving the LCD the pins should be good if LCD working properly.
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- Posts: 11
- Joined: Sat Apr 25, 2015 8:06 pm
Re: Missing button response
I am back on this project.... I have measured everything in the V/DIV circuit...
The only thing found in error was the resistance reading across R-26...
It is supposed to be 10 K, It measures 5K.
I replaced the resistor with another 10 K resistor and received the same results.
Conclusion:
There is a 10 K parallel path across this resistor.
I have traced the circuit and can only conclude that the processor itself is faulty....
I can find no obvious PC board faults...
DB5 is NOT pulled low with the button press.
Photos are attached.
Re: Missing button response
You can try to reduce the 1K resistor to like 470 ohms.
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- Posts: 11
- Joined: Sat Apr 25, 2015 8:06 pm
Re: Missing button response
Very strange symptoms..
Voltage sensitivity can be adjusted directly upon boot of the system, and subsequent key press will not re-select it.
Everything appeared to be working except for the sensitivity setting.... but then the analog board quit generating the square wave signal..
The more I troubleshoot the system the deeper in trouble I seem to get....
It is a beautiful little design... IF only it worked....
System now boots and then crashes to a white screen....
I am really disappointed... It would have been a fun tool in my tool box...
If I find time, I might try to reflash the program.... I assume this is possible?
Re: Missing button response
Did you check the switch itself? Please try shorting the switch with a wire or tweezers to see if V/DIV get selected. For the crash issue what power supply you used? Many users use a small 9V battery. This kind of battery would dry very fast if used to power the scope.