Duet 2 Wifi fried?

incurio

I am running duet 2 wifi board on e3d toolchanger.

I have all 4 tools on my device and needed to rebuild tool 2 due to a print failure that clogged up the hotend.

When I picked up tool 2 and proceeded to turn on the hotend heater it became unresponsive. I was re-using a heater component I had recovered from another tool for my rebuilt hotend, which was connected to a new thermistor same part cooling fans and hotend fans.

I shut down the printer and powered it again and it is only showing a blue LED light. The blue led light that was coming on was the one at the same level as the motor connections and not near the sdcar. I couldn't connect to the printer any more. Web interface was not up.

I then proceeded to plug in the usb cable to my laptop after verifying that the sdcard was not corrupted.

Wifi came back up and I was able to connect to my printer. The 2 led lights on duet 2 near sdcard slot lighted up and appeared to look ok. I even attempted to home the printer but that operation failed, which I expected since 5v doesnt have enough power for that.

I also measured the voltage at the dc power out to the duet 2 , when the blue light was on and it was 24v .

Any help would be appreciated to trouble shoot this further.

Thx

droftarts

@incurio It sounds most likely that the 5V regulator may have blown. This may have been caused by a short in tool wiring, hard to say. Check this guide for diagnosis https://docs.duet3d.com/User_manual/Troubleshooting/Duet_wont_respond and post a good, clear image of the board, particularly the area around the 3.3V and 5V regulators, U2 and U3. Replacement parts are available, see https://docs.duet3d.com/en/User_manual/Troubleshooting/Parts#voltage-regulators-1

Ian

incurio

@droftarts here is photo when powered up using the micro USB

There is a red led light on near left side of image, I hadn't noticed that before.

Will fixing this require soldering work to replace fuse?

Thx

droftarts

@incurio I can't see any obvious signs of damage on the 5V and 3.3V regulators, but that doesn't necessarily mean that they are okay. The lit LED is the Z endstop indicator LED, see https://docs.duet3d.com/Duet3D_hardware/Duet_2_family/Duet_2_WiFi_Ethernet_Hardware_Overview#led-indications
You appear to have a Z endstop plugged in (though no X or Y endstop?), so it's probably not relevant.

It's difficult to tell what is at fault. I would disconnect everything, then power the board only via mains power. If the 5V and 3.3V LEDs come on, and using a multimeter you can read 5V and 3.3V on some pin that provides these, it's probably a short in the wiring. If they don't, it could still be a short, but it has caused the failure of at least one of the regulators, probably the 5V regulator.

Ian

incurio

@droftarts I measured the resistance of the heating element and it showed very little resistance 0.3 , I think this is the culprit. It is the only used component that I used.

Assumming this is correct, what is the fix for this? Do you have a part I should look for to attempt a fix?

thx

droftarts

@incurio If the heating element shorted, probably the main fuse has blown, rather than the voltage regulator. Check the 7.5A fuse by the power input.

Ian

incurio

@droftarts

Here is 7.5A fuse and 1.5A side by side.

I think 7.5A is blown. Not sure about 1.5A it looks clean.

I checked the 15A fuse also and it looks clean it has a connecting metal strip

Please Advise,

Thx

incurio

@incurio I replaced 7.5 and 1.5 fuse and it is working, thx

droftarts

@incurio The 7.5A fuse is definitely blown. The other fuse is for the fans, and looks okay; it should be a 1A fuse.

Ian