The old wire (also pictured) looks even more suspect when removed - so I'm pretty happy I have the culprit.
Can you confirm that the 1.04 board needed this link to bring ground to the ESP? I had expected it to be providing ground to the SDCard shell, which is why I didn't pay it too much attention before.
Thanks. I think that's the conclusion I was coming to, but its very reassuring to hear it from you 
Its well in my capabilities so i'll get on with it now!
I'm UK based.
@dc42 I think I brought it direct, but it may have been via E3D. It would have been around this time two years ago (probably just over two years ago based on my forum account !)
I should really have RMA'd it when I first had issues, but I had a lot of printing to do and couldn't go back to the old board having butchered the wires.
I know i'm well in to "you're on your own now" land, but it is at least a land I recognize 
If I had to replace the ESP I do have the tools (and the ESP!) to do so - as long as after doing so I could just tell the board to install firmware and it would do it.
What I really wanted to avoid is soldering it in and then finding that it needs some bootstrapping firmware - but it seems more like a power issue than a dead ESP issue, so I think i may have dodged that as an option anyway.
Its not terribly easy to capture what i mean, but this enameled wire doesn't seem to cause continuity between the ESP pad and the SDCard shell. Where the wire enters the solder blob the solder is pulled around the wire rather than wetted to it. I can only assume that the ESP is getting ground from elsewhere, at least some of the time. Perhaps there is a partially soldered thermal pad, perhaps there is a pin that is pulled low by the duet board hard enough to act as the system ground through the parasitic diodes on the GPIO?
Very weird:
There is a bodge wire between the SDCard and the ESP ground which looks poorly soldered, the sdcard end tests as ground, the ESP end tests as NC.
Taking a wire from the connector to the esp shell makes it wake up and I can then start the wifi from the USB.
Even more oddly, now woken it continues to operate!
I have been using Duet2 for a while.
when I brought it the wifi was a bit unstable, but I put new solder on the joints and it was happy for about a year.
Today, between prints and without removing power while my printer and laptop were sharing a isolated network router (no other devices and no uplink) the printer stopped responding to the network. The router shows only the laptop and no other devices.
Usually (IIRC) the ESP blinks very briefly on power and the flashes as it looks for network going solid when it has a connection.
Now it is always dark.
I can connect to the printer via USB and issue commands.
The firmware has not been changed recently, certainly not between the working and the failed state.
M115 gives :
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.1.1 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2020-05-19b2
If I use M552 S0 I get
WiFi module is being started
If I try to reinstall the firmware already on the SDCard I get
Trying to connect at 230400 baud: failed
Trying to connect at 115200 baud: failed
Trying to connect at 74880 baud: failed
Trying to connect at 9600 baud: failed
Error: Installation failed due to comm write error
I guess I am out of warranty. Is there anything I can check?
Writing this post made me think more carefully about search terms, they lead me to find a partially unhelpful thread, which gave me more search terms......
And that lead me to https://devhub.io/repos/chrishamm-DuetWebControl
TLDR;
Last Christmas I was given an Alexa, and I didn't want it...
Now i'm too lazy to walk to the radio to turn it on, and the light switches are going the same way.
But as I walk down the road of home automation, it seems that the printer is a thing that I would really like to get stats on (and do things like trigger a light flash when done).
Can the status be polled simply over HTTP, or is there any way to get status over SSH (even firing GCODE at it would be sufficient).
I'd like to get Hotend/Bed/homeing/printing. I could infer "printing" by looking at the print head position and alter the end gcode.
@sethipus Thank you This appears to be it. I thought I had done a set of tests to isolate that, but something must have been wrong with them, my test print seems more solid now!
setting: combing mode = off
so i don't think its that 
Hi, I fitted a D3DWifi to my Ender3 and I don't know if I have it configured correctly, but I have a weird issue printing.
I'm printing with Cura4.2.1 but I've tried 3.6.0 and have the same issue (but less clearly as the profile is for the CR10 and a little messy).
My printer is modified with "direct drive" (really a short bowden - https://www.thingiverse.com/thing:3373107)
If I print a stringing test https://www.thingiverse.com/thing:2219103 then the result looks pretty good.
I have retraction set to 1mm@25mm/s, Prime 50mm/s, but i still get this if i turn retraction off.
Coasting is switched off (makes no odds)
I have Pressure Advance set with M572 D0 S0.250, but this seems to make no odds.
At the start of a extrusion there just appears to be a section where the extrusion doesn't happen, or if it does it grossly under extrudes. I can move this one around the print by changing the z-seam
Here you can see it on the top of left starting the external wall, and not so obviously at the bottom right starting the inner wall.
Finally, here you can see it so pronounced that you can peer through all layers of the wall and into the infill
I'm stumped, any ideas?
