Have been working with my Yukon board this week and this morning I hit a problem. I plugged in the USB cable and I have no com port, so I tried powering off and holding the boot/user button when I powered the unit up (still plugged in) - no drive was displayed in Windows 11. I subsequently tested the unit with multiple cables - confirmed they were data cables (work with my phone) - removed all of the daughter boards (2x big motor and 1x wireless) and still the same result. The green pwr led lights and so do the A and B leds, which I don’t remember seeing before. Any ideas?
You should always get back into boot mode by holding the boot/user button and cycling the power, as you describe. This is a system level feature of the RP2040 chip. In this mode the green power light should be on and the A and B leds should be illuminated dimly. If that is happening, and since you’ve verified your cables, then I suspect it is a temporary issue with your computer rejecting / disabling that USB port. I have encountered this before with various RP products, it’s like Windows gives up after so many connection/disconnections of the same device.
My suggestion would be to first test your USB port with another device such as your phone. This will tell you if the port is disabled. If it is then try Yukon on a different USB port, or reboot your computer so the device comes back up.
I have tried it on two other machines and they all behave the same. What I have noticed is the however I power it up I always get the pwr led and the A and B leds, whether I hold the boot/user button or not. I have run a continuity test over the 4 momentary switches and they all appear to be okay (I was hoping the user/boot may have been stuck closed, but alas no).
Anu other ideas, is there a way to hard reset the board? I have my code backed up.
Since its always entering boot mode when you power it up, that suggests it’s flash has got corrupted and it needs a new UF2 uploading to get Micropython back on it. You say though that a disk drive never shows up though regardless of USB port and machine used?
Entering Boot mode and uploading a new UF2 file is the way to hard reset the board…
Can you show a picture of the illuminated LEDs just to confirm it’s in this mode?
Also, do you recall what you were doing when the issue first occurred? Based on your description I am wondering if an electrical fault has happened somehow that has damaged the RP2040. I feel it to be unlikely though.
I am using the Yukon to control an old Arlo chassis with 12 volt worm gear drives with encoders. The only other thing I had done to the board was solder a set of header pins to the I2C port, they were removed today while looking at this issue, in case I had shorted something, it all look fine under my magnifier but I removed them anyway.
Don’t worry too much I have ordered another Yukon today, so should have it early next week. I just hope its not one of the big motor boards that has popped and has caused the Yukon to fail due to pumping it too much voltage.
Thanks for the photo. That does indeed look like it’s in boot mode.
Depending on when you brought your original Yukon, it’s perhaps worth reaching out to support to see if they can sort you out with a replacement. Include a link to this forum thread to skip the usual troubleshooting steps.
Just for completeness: you also have the debug-port on the Yukon. But it is a bit of a learning curve to set up the environment. And in your case, I doubt that it is worth it.
