Duet 2 Ethernet - No 3v3 Power

jbschwartz

Hello,

We have a Duet 2 Ethernet (v1.04) running an E3D ToolChanger and all has been well for a little under a year.

This morning upon power on there was no response from the machine. We noticed that the 3V3 LED was not illuminated (24V and 5V were illuminated). Our configuration uses an external 24V and 5V power supply (with the jumper set to E_5V). I tried disconnecting the 5V external supply, flipping the jumper to I_5V_EN, and repowering the machine but this made no difference.

I've since fully disconnected the Duet 2 board from the machine. I tried a straight USB connection (without external power) but got similar results (no 3v3 rail).

There is no visible damage to the board; the two power ICs U3 and U2 look fully intact. With the Duet disconnected, I measured resistance across pins 2/4 (GND) and 3 (OUT) on U2 and found ~ 1 ohm-- so it appears something on the 3v3 rail is short.

If there is any other trouble shooting advice, I'd appreciate it.

Thank you,

James

Phaedrux

Does anything get hot soon after 5v USB power is applied?

When and where did you purchase the Duet?

Have you tried blowing some compressed air on the board? Sometimes that can clear out debris that can cause a short.

jbschwartz

@phaedrux said in Duet 2 Ethernet - No 3v3 Power:

Have you tried blowing some compressed air on the board? Sometimes that can clear out debris that can cause a short.

Thanks for the suggestion. I gave it a thorough once over with compressed air.

Does anything get hot soon after 5v USB power is applied?

I powered the board with a bench top supply for several minutes. Current draw was very stable; it pulled 80mA the whole time. None of the components are warm.

Does the 3v3 regulator have short circuit protection? If not, it may just be that that regulator is not coming on.

When and where did you purchase the Duet?

October 2021 through Filastruder. Tim at Filastruder asked me to make this forum post.

Thanks.

Phaedrux

Can you grab some close up well lit photos of the board?

jbschwartz

@phaedrux Sure. Please see below. Can re-take if there's something you want to see-- just let me know.

Phaedrux

Please send an email to warranty@duet3d.com and CC your reseller. Include a link to this forum thread and the details of your original purchase. You'll receive a reply with a form to fill out.