That is just a simple pull-up resistor to Vdd and will not cause a lock-up. It was changed to 1K to fix erratic control of the jog sw.
It can be fixed very simply by placing a 1.2K chip in parallel with the 10K. I did that with my DFU jumper mod so my 2.8" Nano goes into DFU the same way the 4" unit does.
All the original NanoVNA and H units earlier than 3.4 had a 10K and none of them have a lock-up issue, so it may be a 'sensitive' or even counterfeit uP chip. I think the jog sw was changed to interrupt control from polling in the original firmware (correct me if I'm wrong) and there may be an issue with the interrupts on the chip.
Jack should check the Vdd line to ensure it is 3.3 volts and not higher or lower as that would cause issues.
Jack should also try installing FW from edy555 (January 2021) and Hugen (June 2021) and see if there is still an issue.
toggle quoted message
Show quoted text
On Wednesday, July 21, 2021, 1:38:01 p.m. EDT, Gyula Molnar <gyula.ha3hz@...> wrote:
Larry,
? remote repair is a difficult thing because if I see the thing in question directly I will look at more options.
For v3.3, R5 = 10k, this changed to v3.4, it changed to R5 = 1k.
I didn't look back on the cause, but it may be the cause.
73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( ) ***
