Everything has been working as before with the new cards. All peripheral connected to the duet was functional as before the malfunction. I have reduced the PSU voltage from 25.8V to 24.1V to be within specifications. I'm also monitoring the min/max voltages reported by the duet every now and then. I also installed a WIFI repeater close to the duet, since there is a thick floor between the router and the duet to improve the signal strength.

Could you use styrene-acrylonitrile (SAN) instead of HDPE for the side panels?

HDPE: https://plastics.ulprospector.com/generics/27/c/t/polyethylene-pe-properties-processing/sp/5
SAN:
https://plastics.ulprospector.com/generics/47/c/t/styrene-acrylonitrile-san-properties-processing]

SAN has a high Flexural Strength, and 1200X800X4 mm sheet is ~35€ and is transparent.

What are the important mechanical parameters of the plastic panels of the railCore?

Everything has been working as before with the new cards. All peripheral connected to the duet was functional as before the malfunction. I have reduced the PSU voltage from 25.8V to 24.1V to be within specifications. I'm also monitoring the min/max voltages reported by the duet every now and then. I also installed a WIFI repeater close to the duet, since there is a thick floor between the router and the duet to improve the signal strength.

I tested my probe at 5.15V and it still worked as before.
The DC current consumption was ~ 700uA when the integrated LED was off, and ~5mA when the LED was on due to close proximity to a screwdriver.

Sales helped me to solve the issue very quickly.

Is there any information on how to avoid the problem happening again from a user perspective?

I will probably add a small fuse on the 5V and thereafter a shunting ~ 5.4V zener to the ground on the cable between duet2 and the panel to avoid future overvoltage of the panel. Are the Absolute Maximum Ratings 6.5V for the 5V input of the panel?

Connecting a USB cable to X3 results in a rapid temperature increase in (at least) DA1.
Connecting the bench supply to X1:

50 mA , 1.8V
100mA , 2.0V
200mA 2.2V
300mA 2.4V
400mA 2.6V
500mA 2.7V
600mA 2.8V - Aborted

U2 seems to get hot, no signs of light from the panel.

Hi

Thanks, I filled in the Warranty Form.
I forgot to mention that the PanelDue 5i was connected to the board. I am not convinced that it survived.
I can test it with a current limited bench supply @ 5V, (if you tell me what to limit the current supply ), or I could just send it in as well so it can be verified or replaced. The cards were bought together.
The micro-USB connector X3 on PanelDue 5i, should it be able to power the board stand alone?

Hi

My rather new duet2 wifi rev 1.04b started to smoke when I was probing my bed. U3 burned a hole in itself just as others have shown in pictures.
I have used a 12V M12 inductive probe for 2-3 weeks, but yesterday I changed to a smaller 5V M8 inductive probe. (The 12V for the old probe was from an external step down converter.)
For the 5V probe, I used the 5V from the duet expansion connector. I would say that it did around 40 probe points, but then suddenly U3 started to smoke. My rail was 25.8V. No other active components were connected to the card more than the probe and the main PSU.

Anyone knows why? Have anyone checked the 5V AC power spectrum, with a 5V inductive probe connected and modulating the distance. My first thought when I found others with smoked U3, was regarding the phase margin of the closed loop of U3 when attaching a non-resistive load to 5V. But it is just a very wild guess.

I ordered the card directly from duet3d.com 16/04/2019.