Duet 2 WiFi only connects via USB

FL630

About a month ago I set up my Duet 2 WiFi on my new printer and it all worked great. I was waiting for a load of parts so finally got around to fitting then today. Turned on the duet and no success, it wouldn't connect, only one red LED and no connecting via the .local address or finding the 192.168.1.*** way.

I followed the troubleshooting and connected via USB and the web interface comes up almost instantly and I get a lot more lights on the board (Inc the blue one on the WiFi antennae). I've re-run the whole connecting to wifi part on the website to re-configure to my router.

Going through the terminal on my Mac shows it is connected to my router.

Any idea where to start with the troubleshooting so I can connect via WiFi when it' being powered by my PSU, not through USB?

Edit, further investigation: When connected via USB, I have blue Wifi LED, red LED between USB and reset, green and red voltage lights. When connected via the PSU (output verified with multimeter at 24.0v) it shows the blue power LED. When powered by USB and PSU, all LED's light correctly and the system functions as intended. Does this indicate a power issue?

dc42

That indicates that the 5V regulator is not operating. Is the I_5V_EN jumper still in place? is there any sign of damage to the small square chip labelled U3 that is quite close to the VIN connector?

FL630

Thanks for replying @dc42, looks like there is a burn mark on the U3 chip. What could have caused this, is the board essentially dead now?

dc42

I am sorry, the 5V regulator has failed on your Duet. If it is a genuine Duet purchased from one of our resellers or direct from Duet3D, please ask for a replacement under warranty, which I hereby approve.

FL630

@dc42 it certainly is a genuine one. Thank you, I'll get in touch with E3D.

FL630

New board arrived today @dc42, thanks to E3D's excellent service. Thank you for approving the replacement.

I've wired it all up as per the old board and the U3 chip is still in one piece. Can I ask what could cause the U3 to burn out so I don't replicate the same mistake? Could it have just been faulty or is it likely something I may have done? I'd really like to avoid another fried 5v rail!