Bitaxe – Not Hashing / Zero Hashrate

Unplug the 5 V barrel jack for a full 10 seconds (count it out loud — longer than you think). Reconnect. This clears roughly half of BX_NO_HASH events by forcing the TPS546 regulator on Gamma/GT to re-initialize after a latched power fault. A soft reboot via the web UI does not do this; only physical power removal does. Watch AxeOS for 3 minutes post-reconnect. If hashrate climbs toward nameplate (Supra/Ultra ~500-700 GH/s, Gamma ~1.2 TH/s, GT ~2.4 TH/s, Hex ~3 TH/s) you are done.

Confirm you are powering the Bitaxe through the 5.5x2.1 mm barrel jack with a regulated 5 V / 5 A supply — not USB-C. USB-C on every current Bitaxe is serial/firmware only; it will boot the ESP32 and answer the dashboard, but the ASIC never gets power. If you are unsure, pull the USB-C cable entirely and power exclusively via barrel. If the device powers down, you had it wrong. If it keeps running, barrel is connected and the fault is elsewhere.

Verify the supply itself is not a sagging phone charger or Raspberry Pi PSU. Cheap supplies droop to 4.5 V under a 20 W load and produce identical symptoms to a dead ASIC. If you are using anything other than a dedicated Bitaxe 5 V / 5 A PSU or a bench supply, swap it out before doing anything else. This single swap closes more BX_NO_HASH tickets in the D-Central queue than any other action.

Open AxeOS and check Settings → Pool. If the pool URL, port, or worker name is wrong, the device may be hashing internally but nothing reaches a pool, which in most dashboards still reads 0 GH/s. For solo mining, confirm `public-pool.io:21496` or `solo.ckpool.org:3333` style URLs and a valid BTC address in the username field. For pooled, confirm the stratum URL exactly matches your pool's current documentation.

Reboot the miner via AxeOS Settings → Restart. If this is the one path that fixes it temporarily, you have an ASIC serial stall ('Flatline of Death') — a firmware issue, not hardware. Proceed to step 7 to get on current firmware. Frequent soft-reboots are masking a real bug and will eventually fail to recover, so do not treat this as a permanent fix.

Multimeter on DC, probe the 5 V barrel tip (center positive) while the ASIC is attempting to load. Expect 4.95-5.15 V sustained. Below 4.85 V under load = PSU sag. Swap to a known-good 5 V / 5 A supply and retest. On Gamma/GT, sag below 4.8 V trips the TPS546 into power-fault state and the ASIC never initializes. This is the single most-diagnosed root cause across Gamma-family repair tickets at D-Central.

Flash the latest stable AxeOS via the official Web Flasher over USB-C. Download the factory .bin for your exact board revision from github.com/bitaxeorg/ESP-Miner/releases. Connect USB-C, put ESP32 in download mode (hold BOOT, tap RST, release BOOT), open the Web Flasher, select the correct image. Critical: BM1366 image on a BM1370 board bricks it. Double-check silkscreen. Reconfigure WiFi and pool. Firmware corruption from interrupted OTA is a common cause and the fix is a factory USB-C reflash, not another OTA attempt.

Reseat the ASIC heatsink. Remove heatsink screws, lift carefully, inspect for cracked thermal pad, dried paste, or a visible air gap over the chip. Clean old paste with 99% IPA and a lint-free wipe. Apply a thin uniform layer of Arctic MX-6 or Thermal Grizzly Kryonaut — pea-sized, no glopping. Retighten evenly. A chip thermally throttling to zero looks identical to a dead chip from the dashboard; this rules it in or out and fixes more boards than you would expect.

Check barrel jack mechanical integrity. The 5.5x2.1 mm jack works loose under cable strain, especially on desks with the PSU dangling. Wiggle gently: if the device reboots, browns out, or the voltage on your multimeter jitters, the jack is loose. Add strain relief (cable tie to chassis), hardwire solder the jack, or replace with a cable that has a locking collar. Flickering power on Gamma/GT = a TPS546 fault trigger every single time.

Check AxeOS Logs tab for specific error strings. `Power Fault Detected` = TPS546 issue, return to step 6. `ASIC not responding` or `no nonces` = UART/serial chain, proceed to Tier 3. `I2C handle not initialized` = EMC2101 fan controller race condition (ESP-Miner issue #1291), firmware update to v2.9.1+ is the documented fix. `Selftest FAIL` = hold BOOT on next power-up to skip selftest, then reflash factory with a version past the selftest-skip fix.

Connect to USB-C serial at 115200 baud using screen /dev/ttyUSB0 115200 (Linux/Mac) or PuTTY / Arduino Serial Monitor on Windows. Watch boot logs. A healthy boot shows `Chip detected: BM1366/1368/1370`, `ASIC frequency set`, `Starting stratum`. A dead chip shows `ASIC not responding` or `0 chips detected`. A multichip board reporting fewer chips than physical count points to a broken daisy-chain — the first chip after the last-detected one is the likely failure. Serial logs are the single most diagnostic tool on a Bitaxe.

For multichip boards (Hex v303/v304, UltraHex, GT dual-chip), inspect solder joints at each chip's UART / Vcore pads under 10x magnification. Cold joints, hairline cracks, lifted pads are common after shipping drops. Reflow the suspect chip: remove heatsink, flux the BGA, preheat PCB to ~150 °C from below, hot-air top-side at 310-330 °C for ~30 seconds with moderate airflow. Let cool naturally, re-paste, reassemble, retest. BM1366-family chips tolerate a reflow cycle well.

If selftest is bricking the device (stuck in selftest loop — ESP-Miner issue #516), hold BOOT on power-up to skip. Flash NVS partition via `esptool.py --chip esp32s3 erase_region 0x9000 0x6000` to nuke stored config. Then flash a factory image past the selftest-skip fix (v2.1.4+ for most boards, later for newer hardware). Reconfigure from scratch. This is the canonical recovery path and the procedure is publicly documented in the ESP-Miner repo.

If AxeOS comes back after firmware flash but hashrate still reads zero, and you have verified power + barrel jack + heatsink, suspect ESD or shipping damage to the ASIC. Three paths: (a) replace the board if under 60 days old and warranty applies, (b) buy a replacement ASIC chip from D-Central parts inventory and reflow yourself, or (c) ship to D-Central for bench diagnosis and chip swap. Path (b) costs a cheap dinner if it works and teaches permanent skills.

For a stuck 'Flatline of Death' — hashrate freezes, pool shows offline, cold boot fixes for hours — confirm you are on the latest stable AxeOS (currently v2.14.x family mid-2026; verify at github.com/bitaxeorg/ESP-Miner/releases). Firmware tracks v2.9 through v2.13 had documented variants of this bug in issue #1053. Enable the watchdog auto-restart feature if supported; otherwise set up an external reboot plug (Kasa smart plug + hashrate API polling is a 20-minute cron script).

Wrong-.bin recovery: you flashed BM1366 firmware on a BM1370 board (or any analogous mismatch). Device boots, web UI works, ASIC silent. Connect USB-C, put ESP32 in download mode (hold BOOT, tap RST), run the Web Flasher with the correct factory image for your silkscreen revision. The fix is always a factory USB-C reflash — OTA from within a wrongly-flashed firmware often fails or re-introduces the mismatch.

Multichip daisy-chain debugging (Hex / UltraHex / GT): flash the ESP-Miner-multichip fork or the current unified build that supports your chip count. Serial console should report `Chip count: N` matching physical chips. If short, isolate by position — chip 0 through chip N — each chip passes UART on to the next. The first missing chip's position tells you where the break is. Reflow or replace as in step 12.

Stop DIY when: (a) you have reflowed a suspect chip and hashrate still reads zero, (b) you do not have a hot-air rework station or USB-C serial access, (c) the board shows visible damage from a power surge or reverse-polarity event, or (d) you flashed the wrong .bin and cannot get the board back into download mode via BOOT/RST. At that point the board needs a bench, a known-good chip, and a professional reflow. Book D-Central Bitaxe repair.

D-Central bench process for a BX_NO_HASH board: USB-C serial diagnostic first (costs us five minutes, saves you hundreds), chip-level continuity check for ESD/surge damage, TPS546 regulator swap if power-fault territory, full reflow with a known-good chip from our salvaged-grade inventory if chip replacement is needed, factory flash with current stable AxeOS, 24-hour burn-in at nameplate hashrate on the bench stratum server. Turnaround typically 3-7 business days Canada-wide.

Ship safe: anti-static bag, small padded box, at least 3 cm foam on every side. Include a note with symptoms observed, firmware version last run, and whether you have tried Tier 1-3 already — this saves us diagnostic time which saves you money. Optional but helpful: include the barrel jack PSU you have been using so we can test the whole power path end-to-end. Bitaxes are small and cheap to ship; a Hex or GT ships for roughly $15-25 CAD inside Canada.