Bitaxe – Bricked After Firmware Flash (Cannot Enter Bootloader)

Power-cycle with a proper USB-C DATA cable (not charge-only). Unplug for 30 seconds, swap to a cable you know carries data (Pixel / iPhone 15 / USB 3.x), plug back in, wait 60 seconds for AxeOS to fully boot. About 30% of 'bricked' Bitaxes recover on this step because the previous boot was killed mid-OTA by a marginal cable.

Open the Bitaxe Web Flasher (bitaxe.org/flasher) in Chrome or Edge. Firefox and Safari do NOT support WebSerial. Click Connect, select the USB Serial Device / ESP32-S3 port, pick your exact model (Supra/Ultra/Gamma/GT/Hex), click Install. The Flasher drives the ROM bootloader automatically. This is the official 70%+ first-pass recovery path.

Force ROM bootloader mode manually if the Flasher can't see the chip. Unplug USB. Press and hold BOOT button (the smaller tactile, not RESET). While holding BOOT, plug USB-C back in. Keep holding for 3 seconds after plug-in, then release BOOT. Do NOT press RESET. Retry Web Flasher.

Try a different USB-C cable AND a different PC. Laptop ports are generally cleaner than desktop front-panel hubs. About 50% of 'Bitaxe won't bootloader' tickets at the D-Central bench are a bad cable, not a bad Bitaxe. Highest-yield fix and costs nothing.

Check Windows Device Manager (or `dmesg` on Linux, System Information on macOS). Plug Bitaxe in, look for a new USB Serial Device or `/dev/cu.usbmodemXXX`. Yellow `!` or `Device Descriptor Request Failed` = USB handshake failing = cable or port problem. Try the manual BOOT-held sequence again.

Full flash erase before re-flash. In Web Flasher click `Erase Flash` before `Install`. This wipes partition table, both OTA slots, NVS, SPIFFS, and factory app. Then install the factory `.bin` for your exact model. Cures partition-table corruption from interrupted OTA. Erase takes 15-30 s; re-flash takes 30-60 s on a 16 MB part.

Install esptool.py manually from a terminal. `pip install esptool`. Bootloader mode (unplug, hold BOOT, plug, release). Run `esptool.py --chip esp32s3 --port COMx chip_id` to confirm, then `erase_flash`, then `--baud 921600 write_flash -z 0x0 esp-miner-factory-<model>-vX.Y.Z.bin`. Terminal errors are FAR more informative than Web Flasher's generic popups.

Download the correct factory firmware for YOUR hardware from github.com/bitaxeorg/ESP-Miner/releases. Gamma/GT use `factory-gamma`, Supra uses `factory-supra`, Ultra uses `factory-ultra`, Hex uses the multichip-fork factory image. A Gamma `.bin` on a Supra boots but traps `asic_init_fail` and reboots forever - looks bricked, isn't.

Inspect USB-C port for physical damage under a jeweller's loupe or phone macro lens. Look for bent pins, solder bridges between CC1/CC2, debris in the socket, or a lifted pad at the footprint. Clear dust/lint with compressed air plus IPA 99% on a cotton swab. If mechanical damage is present, move to Tier 3.

Validate your cable with a USB cable tester (the cheap $10 ones with per-wire LEDs work fine). Most charging cables only wire VBUS/GND/CC - D+/D- data pair is physically absent. These are indistinguishable from data cables without a tester. Thunderbolt or USB 3.x cables, or the ones bundled with mainstream phones, are always safe bets.

UART bootloader recovery when USB-C is physically dead. Solder or clip a USB-to-3.3V-UART adapter (FT232RL or CP2102) to TX0/RX0/GND pads. Power Bitaxe via its normal 5V input. Short IO0 to GND via jumper, briefly pulse EN to GND (hardware reset), release EN, then release IO0. Run `esptool.py --port <UART-COMx> --chip esp32s3 --baud 460800 chip_id`. This bypasses USB-C and talks directly to the mask ROM.

Re-flash via UART at reduced baud if 921600 fails. Slow to `--baud 230400` or `--baud 115200`. UART on flying leads has worse signal integrity than a clean USB trace. `write_flash` at 115200 on a 16 MB part takes 6-8 minutes - be patient, don't unplug, don't move the wires.

Re-seat or re-solder the USB-C connector if Step 11 worked but USB-C didn't. Under magnification, look for cold joints, cracked fillets, or lifted pads. Flux each pin, reflow with a fine-tip iron (~330 °C). Lifted pads: scrape back 0.5 mm of soldermask to expose fresh copper and bridge with thin wire. $10 in parts, 20 minutes if you've done it before.

Cross-flash an alternative firmware to confirm the ESP32-S3 is alive. From UART bootloader, try bitaxeorg/ESP-Miner stable, shufps/ESP-Miner-NerdQAxePlus (for NerdQAxe), or BitMaker-hub/ESP-Miner-NerdAxe. If any boot and show their native UI, the ESP and flash are fine - the original firmware was the problem. Return to correct stock is another flash cycle.

NVS factory restore. Post-v2.0.0 firmware requires valid NVS (MAC, model, ASIC calibration). If `erase_flash` wiped NVS, after re-flashing factory the Bitaxe boots but shows `Model: Unknown` and won't drive the ASIC - looks bricked. Fix: in AxeOS manually set ASIC Model, Frequency, Voltage (Gamma: BM1370, 525 MHz, 1200 mV default). Or `write_flash` a known-good NVS binary at the NVS partition offset.

Stop DIY (Tier 4): UART recovery also fails with `Failed to connect`, OR the ESP32-S3 shows physical damage (scorching, swollen epoxy, diagonal crack), OR you measured reverse polarity on 5V input and the 3.3V LDO smells burnt, OR the USB-C footprint has torn pads past hand-reflow. Ship to D-Central - we pioneered the Bitaxe ecosystem and stock ESP32-S3 modules + USB-C connectors. A $30-50 repair on a $150 miner is a no-brainer.

D-Central bench process: run the Bitaxe through UART recovery with bench fixtures and a known-good 3.3V UART harness. If that fails, swap the ESP32-S3 module (hot air at 320 °C, new module pre-flashed with correct factory for your variant), replace damaged USB-C connectors, repair lifted pads with copper-tape jumpers, burn-in 4-6 hours at nameplate hashrate before shipping back. D-Central built the first Bitaxe Mesh Stand and first Bitaxe / Bitaxe Hex heatsinks - we see every Bitaxe failure mode first.

Ship safely to D-Central. ESD bag, foam cradle inside a rigid box. Include a note describing symptoms (what firmware was being flashed, whether cable/PC were swapped, whether UART recovery was attempted). If you soldered UART leads, mention it - we remove them. Include any heatsink or fan accessories so we can full-stack bench test. Canada Post small-parcel or UPS Ground; we receive at D-Central HQ and open within 48 hours.