Fried Z1284PI on duet 3 6HC

[stefvandermeer]

Hello,

I am afraid i got fairly lucky while working on my new tool changing 3d printer. I was testing stepper motor functions for a custom tool lift when i was greeted with the smell of fresh burning electronics. after I noticed the smell I killed the power to the mainboard. after closer inspection I was unhappy to see the Z1284PI was burnt. I am puzzled about the cause of this occurrence, the stepper motors I was testing where plugged into one of my 3hc expansion boards. the fact that a component on the mainboard shorted somehow seems odd to me since the mainboard was not powering anything apart from some LED lights. after I killed the power I tried powering the duet with my desktop power supply with the usual 24 volts, the 24 and 12 volt rails where working appropriately but the 3.3 and 5 volt rails weren’t.
before this all motors where working fine but somehow I couldn’t get the sensor inputs to work, but this could also be a problem with the switches I am using.

stuff plugged in: (duet 3 6hc)

steppers on out0 to out5
bed heater on out0
24v led strip on out2
bed thermistor on temp1
panel due on io0
duet 3hc thru can bus
Z end stop on io1
bed probe on io2
tool lift end stop on io3

stuff plugged in: (duet 3 3hc) 1 and 2

stepper motors on first drives of both boards

I hope someone out there can help me out.
thanks in advance

Stef

[dc42]

@stefvandermeer I'm sorry to hear that your board has failed. Please tell us:

• What version Duet 3 main board was it?
• What sort of LED strip was it driving, and how many LEDs were in it?
• What VIN voltage do you use?
• When did you purchase the Duet 3?

[stefvandermeer]

@dc42

I bought the board in July in preparation for my upcoming printer build. The board was version 1.0. I am powering the printer with a 24 volt meanwell powersupply, I could provide the model number of this unit when needed. I was just powering a 50 mm section of 24 volt led strip to use as a work light.
I hope this information helps,

[stefvandermeer]

@stefvandermeer the Led strip I was using was only 9.6 watts per meter and I was only using 50 mm

[T3P3Tony]

@stefvandermeer it looks like there was a fault that damaged 5V regulator. What confuses me slightly is you said that the only thing being powered was the LED lights but it looks like a lot more was connected.

The Z1284PI has over current protection so it should shut down in a normal short condition not get damaged.

@dc42 may have a few more questions.

[T3P3Tony]

@stefvandermeer Please contact warranty@duet3d.com to arrange a replacement as in a normal overload situation the regulator should shut down, not blow. that said i would very carefully check your wiring for everything plugged into the 6HC for shorts. when you get the replacement board I would plug things in one at a time and test between adding each connection in case there is something with an odd fault causing this.

[stefvandermeer]

@t3p3tony alright, I will contact warranty support thanks for your help and I will be more careful next time