Spurious Resets v1.6

[+Stephen]

I recently assembled a new FujiNet which I believe is v 1.6.  It is for the 576NUC and has a cart board adapter.  The issue I am having occurs both when the machine is powering the device, as well as when the 576 is completely powered down, and only the USB cable is powering the Fujinet to run the debugger.  Basically, I am getting "phantom" key presses of the C button (reset).  All 3 types of presses are detected (long short, double tap).  Physically the button feels ok.  It clicks when pressed and releases fully when I let go.  But given that it is resetting the device, it makes it unusable.  Is there anything that could cause this electrically, or should I first check for mechanical damage (faulty button)?

 

Here's is a truncated log file - the machine was powered off, sitting on a stable surface and I never once touched the button.

Using 'COM3' as serial port.
Showing logs:
[14:05:57]SNTP time sync event: Mon Oct 25, 14:05:57 2021 -0400
[14:09:11]BUTTON_C: DOUBLE-TAP
[14:09:13]BUTTON_C: SHORT PRESS
[14:09:37]BUTTON_C: LONG PRESS
[14:09:41]BUTTON_C: SHORT PRESS
[14:09:46]BUTTON_C: LONG PRESS
[14:10:17]BUTTON_C: LONG PRESS
[14:11:15]BUTTON_C: LONG PRESS
[14:11:16]BUTTON_C: SHORT PRESS
[14:11:19]BUTTON_C: LONG PRESS
[14:11:23]BUTTON_C: LONG PRESS
[14:13:32]BUTTON_C: LONG PRESS
[14:14:15]BUTTON_C: LONG PRESS
[14:14:20]BUTTON_C: LONG PRESS
[14:14:35]BUTTON_C: LONG PRESS
[14:15:16]BUTTON_C: LONG PRESS
[14:17:44]BUTTON_C: SHORT PRESS
[14:17:46]BUTTON_C: LONG PRESS
[14:17:49]BUTTON_C: LONG PRESS
[14:18:13]BUTTON_C: LONG PRESS
[14:18:45]BUTTON_C: LONG PRESS
[14:20:54]BUTTON_C: LONG PRESS
[14:21:15]BUTTON_C: LONG PRESS
[14:21:28]BUTTON_C: LONG PRESS
[14:24:13]BUTTON_C: DOUBLE-TAP
[14:24:14]BUTTON_C: DOUBLE-TAP
[14:24:15]BUTTON_C: DOUBLE-TAP
[14:24:17]BUTTON_C: LONG PRESS
[14:24:21]BUTTON_C: SHORT PRESS
[14:24:23]BUTTON_C: LONG PRESS
[14:24:53]BUTTON_C: SHORT PRESS
[14:24:55]BUTTON_C: LONG PRESS
[14:25:07]BUTTON_C: LONG PRESS
[14:25:11]BUTTON_C: SHORT PRESS
[14:25:13]BUTTON_C: SHORT PRESS
[14:25:16]BUTTON_C: LONG PRESS
[14:26:19]BUTTON_C: LONG PRESS
[14:26:57]BUTTON_C: LONG PRESS
[14:27:15]BUTTON_C: LONG PRESS
[14:27:15]BUTTON_C: SHORT PRESS
[14:27:18]BUTTON_C: LONG PRESS
[14:28:02]BUTTON_C: DOUBLE-TAP
[14:28:05]BUTTON_C: LONG PRESS
[14:28:11]BUTTON_C: LONG PRESS
[14:28:37]BUTTON_C: SHORT PRESS
[14:28:40]BUTTON_C: LONG PRESS
[14:29:55]BUTTON_C: DOUBLE-TAP
[14:29:57]BUTTON_C: DOUBLE-TAP
[14:29:58]BUTTON_C: DOUBLE-TAP
[14:30:03]BUTTON_C: LONG PRESS
[14:30:04]BUTTON_C: SHORT PRESS
[14:30:09]BUTTON_C: LONG PRESS
[14:30:37]
Serial port closed!

[mozzwald]

40 minutes ago, Stephen said:

Is there anything that could cause this electrically, or should I first check for mechanical damage (faulty button)?

If the pull up resistor for Button C (Safe Reset) is missing or improperly soldered then you would see this. It's a pull up to 3v3.

[+Stephen]

Hmm - I meant to post a reply here.  Not sure why it didn't post.  Anyhow - I have tried a stronger pullup resistor on IO14 pin, and I am hoping this will fix the issue.  With the 10k, I would get 3.27VDC between IO14 and ground until the FujiNet booted up.  Then it would drop to 1.9V.  With the additional 10k in parallel, I am getting a steady 3.27VDC, and 0.00VDC when the button is pushed and held.