Preview build — page text is a draft awaiting human review. Code badges come from real compiles. The flasher is real but not yet hardware-tested; the Playground is still a preview.
Get Started
Bootloader · Pico

Fix: copied the .uf2 to the Pico but nothing happens

The drive vanished (or came back) but no blink. Wrong UF2 for the chip (RP2040 vs RP2350), Pico W LED pin, MicroPython that just waits, or a full flash.

Raspberry Pi PicoRaspberry Pi Pico WPico 2 / Pico 2 WRP2040-ZeroUpdated 3 Nov 2026

Community draft — report a mistake

What you see

OutputOutput
Copying blink.uf2 to RPI-RP2 (E:)
Error 0x800701B1: A device which does not exist was specified.

(drive disappears, LED stays off — or the drive comes straight back)

Drag-and-drop flashing a Pico is simple: copy the .uf2 to the RPI-RP2 drive and the board reboots into it. When nothing seems to happen, the copy almost always worked. Either the file was for a different chip, or the firmware is running in a way you can’t see.

Check the chip first (RP2040 or RP2350), then what the firmware is meant to do. A Pico W blink needs the Pico W build.

Quick fix — try in order

  1. 1

    Ignore Windows' “Error 0x800701B1”

    The Pico reboots the instant the copy ends, so the drive vanishes before Windows finishes tidying up. The firmware was written; this message is harmless.

  2. 2

    Match the UF2 to the chip

    Pico and Pico W use RP2040; Pico 2 and Pico 2 W use RP2350. An RP2040 UF2 copied to a Pico 2 is ignored and the RP2350 drive stays (or comes back). Download the build for your exact board.

  3. 3

    Pico W: the LED isn't on GPIO25

    On the Pico W the green LED is wired to the Wi-Fi chip. A plain Pico blink (GPIO25) runs but shows nothing. Use the Pico W build, or Pin("LED", Pin.OUT) in MicroPython.

  4. 4

    MicroPython installed? It just waits for you

    MicroPython doesn't blink anything by itself. Open Thonny, select “MicroPython (Raspberry Pi Pico)” and the REPL appears — that means it worked.

  5. 5

    Start clean with flash_nuke.uf2

    If an old main.py or a corrupt filesystem crashes the board at start-up, copy Raspberry Pi's flash_nuke.uf2 first (it erases everything), then your firmware.

Why it happens

Why does the drive come back?

The bootloader checks each UF2 block's family ID. Blocks for a different chip are ignored, so after the copy there's nothing new to run and you're still in BOOTSEL mode.

Copied the file to the wrong place

Copying to a different drive letter, or into a folder on RPI-RP2, also does nothing. Drop the .uf2 into the root of RPI-RP2.

Board-specific notes

RP2040-Zero: Has an RGB LED (WS2812 on GPIO16) instead of a plain LED. A standard blink UF2 shows nothing.

Pico 2 W: Needs RP2350 firmware and, like the Pico W, drives its LED through the wireless chip.

↑↓ to move · Enter to open