Missing button response

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derde
Posts: 1
Joined: Tue Sep 26, 2017 2:38 pm

Missing button response

Post by derde »

Hello guys, after completing the soldering everything works except the V/DIV and SEC/DIV buttons ... what can i check/do about that? :oops:
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.
Petroid
Posts: 21
Joined: Wed May 17, 2017 4:50 pm

Re: Missing button response

Post by Petroid »

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).
wimnl
Posts: 1
Joined: Sat Oct 07, 2017 12:41 pm

Re: Missing button response

Post by wimnl »

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.
albenbrewder
Posts: 11
Joined: Sat Apr 25, 2015 8:06 pm

Re: Missing button response

Post by albenbrewder »

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....
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: Missing button response

Post by jye1 »

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.
albenbrewder
Posts: 11
Joined: Sat Apr 25, 2015 8:06 pm

Re: Missing button response

Post by albenbrewder »

sch-1.jpg
Photo-1.jpg
sch-2.jpg
sch-2.jpg (8.34 KiB) Viewed 8616 times
Sorry for the long delay...
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.
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: Missing button response

Post by jye1 »

You can try to reduce the 1K resistor to like 470 ohms.
albenbrewder
Posts: 11
Joined: Sat Apr 25, 2015 8:06 pm

Re: Missing button response

Post by albenbrewder »

analog board
analog board
Main Board
Main Board
Boot Screen
Boot Screen
Boot Screen
Boot Screen
I have reduced the resistor to 470 ohms... with no affect... V/Div button will still not select the Voltage box on the screen
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?
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: Missing button response

Post by jye1 »

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.
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