Burned out diode C91 on the Duet Ethernet board

Patrick_487

Good day,
I have a problem with my Duet 2 ethernet board. My printer hadn't been in operation for a good 1 ½ weeks. I switched it on yesterday afternoon because I wanted to print something again.

Then it had briefly "puffed" and there was a small flash of lightning and it smelled burnt. I immediately disconnected it from the power. Today I looked up what happened there and found that the diode C91 burned out. What you could see now at first sight.

can this be repaired or is it really not possible, as other components that have burned out may also be affected.

The board is around 2.5 years old.

I thank you for your answer.

alankilian

@patrick_487 That's a pretty strange thing to fail.

C91 is a capacitor attached to your bed heating power supply.

The fuse F4 connects it to your main power supply V_IN

Could your main power supply have failed?

I would disconnect your main power supply, power it on and measure its voltage.

Also, I would check Fuse F4 to see if it has been blown up also.

If you get a proper voltage on your power supply, and F4 is not blown, I would clean up C91 (Try to pick the remains off the board, but be CAREFUL not to damage the board) and then turn on the power and see which of the power LEDs light up.

It would be unusual, but maybe you just had that capacitor fail.

zapta

@patrick_487 , you are not running the board on a voltage higher than 24V, right?

Patrick_487

@zapta No, I use 24V on the board

mrehorstdmd

@patrick_487 Did polarity get reversed somehow?

Patrick_487

@mrehorstdmd No, nothing has been changed on the wiring. It was only switched off for 1 ½ weeks

T3P3Tony

@alankilian said in Burned out diode C91 on the Duet Ethernet board:

I would disconnect your main power supply, power it on and measure its voltage.
Also, I would check Fuse F4 to see if it has been blown up also.
If you get a proper voltage on your power supply, and F4 is not blown, I would clean up C91 (Try to pick the remains off the board, but be CAREFUL not to damage the board) and then turn on the power and see which of the power LEDs light up.

these are good things to try

Patrick_487

@t3p3tony I have now carried out the recommendation like this.

Main power supply voltage = 24.0V
Fuse F4 is OK, remnants removed from the capacitor.

Attached is a picture with the LEDs that light up when I switch on the printer.

I also created a diagnosis file via the web control.console.txt

alankilian

@patrick_487

It doesn't seem like anything was damaged.

Are all motions and the extruder heater working if you don't run the bed heater?

Do you think you can replace the capacitor if you get a new one?

dc42

The capacitor isn't vital, its purpose is to avoid the VIN wiring radiating EMI generated by bed heater PWM switching. The board can be used without it.

Patrick_487

@dc42 Hi, am I restricted in any way if the capacitor is missing? And do I have to fear further mistakes or even a fire from the board?

dc42

@patrick_487 you can use the board as normal, it it's just that capacitor that failed.