Dead Duet 2 Wifi... Sort of.

SupraGuy

So I was cutting a CNC job, when the Duet just stopped. Bang, no power to motors, no response on the network, nothing.

No LED lights for 5V or 3V3, just the Vin light, so it was getting 12V power, but no logic power.

Full disclosure, this is my one knock-off. I have 3 other Duet 2 Wifi boards, all genuine, but I wanted one more, and the official supplier out here was out of stock. Still is, it turns out. Looks like they only have the Diet 3 boards now. (I want one for my CoreXY printer, which needs 6 drivers, but that has to wait for now.)

Anyway, I pulled the Duet from the CNC, and decided to see how bad it cooked. As opposed to th e last time (I let a hotend run over the cabling ) when I cooked a bunch of stuff, this time, it didn't seem so bad. The SD card at least wasn't dead. So I plugged it into USB. Hmmm. Recognised device, so turn on the serial monitor, and it connected to the wifi. DWC works.

12V power... nope.

So I suspect that the knock-off 5V regulator has comitted seppuku. It appears not to have taken the wifi module or the MCU with it. The status of the motor drivers is unknown because I have not had both USB and Vin connected at the same time, but I might try that with a USB power brick (I don't know that I want anything that I care about connected to the USB when there's a suspect regulator between 5V and 12V, though I suppose that if it were that bad it would have damaged more stuff on board.)

The moral of the story is one that I've told often enough... The cost of cheap equipment is the cost of the cheap equipment, plus the cost of the expensive equipment to replace it, plus the time and trouble to troubleshoot and replace.

I might give some SMT soldering a try to replace this regulator though. No stock on replacement boards.

Guess I better figure out which is the 5V regulator...

SIam

Long text and short answer U3 is the 5V regulator, and it sounds to me that this chip is dead. I think you have checked the fuses before

SupraGuy

@siam Thanks for the confirmation. Yeah, fuses were the first thing I checked.

The more I probe at this cloned board, the more I appreciate the build quality of the originals.

Edit, looking at where U3 is located, I don't think I can repair this myself, so I'll use an external 5V supply, until I can source a genuine replacement... Or I retire one of my printers.

Phaedrux

@supraguy said in Dead Duet 2 Wifi... Sort of.:

so I'll use an external 5V supply,

This is the way.