How to Recover a Bricked IceRiver After Failed Firmware Upgrade

Hard power-cycle for 60 seconds at the breaker. Not a soft reset — full mains kill for a full minute. Roughly 10% of brick tickets resolve at this step alone because the failure was a wedged daemon state surviving soft reboots. Always try this before anything destructive at higher tiers.

Hold the reset button for the full `20 seconds` until the red status LED starts flashing, then release. Wait `5 minutes` untouched. Factory reset on KS hardware copies the factory partition to the active partition and reboots. If your brick was config-level rather than rootfs-level this recovers it; if nothing happens within 5 min the active partition was already too corrupt to land the reset.

Verify network path before assuming brick. Power on, wait 5 min, check your router DHCP table for the MAC. If a lease is present but port `80` is dead, you have a partial brick — proceed to higher-tier steps. If the MAC is absent, swap Ethernet cable and switch port before condemning the unit; dead ports masquerade as bricks.

Catalogue the brick trigger: mid-OTA, third-party firmware, power event, days/months of stable operation, last known firmware version. This shortens diagnosis time at every higher tier and saves D-Central 30+ minutes per unit if you eventually ship — savings passed back in the repair quote.

Try IceRiver's 'Detect IP' tool from `iceriver.io` one more time. Some bricks present as 'no DHCP' but the unit is answering on `192.168.1.1` (factory default fallback) because DHCP failed. Plug directly into a laptop with a static IP on `192.168.1.0/24` and try `http://192.168.1.1`. Long shot, but free.

Try SD-card recovery boot (KS0/KS1/KS2/KS3 family). Download the official recovery image from `iceriver.io/firmware-download/` for your exact model AND hardware revision (wrong rev bricks further). Write to microSD with `balenaEtcher`. Power off, insert SD, hold reset, power on while holding reset for `5 s`, release. The bootloader detects the SD and reflashes from it over 3-8 minutes. Don't power-cycle during this.

Verify line voltage stability before any flash retry. Multimeter on AC at the wall under load. KS units accept `180-285 V` AC. If line voltage sagged below `190 V` during your previous OTA attempts, that is why the unit bricked — and trying again on the same circuit will brick it again. Move to a stable circuit, ideally UPS-protected, before any flash retry.

Try wired-Ethernet OTA from the same subnet. If the unit answers ping but port `80` is dead, the OTA daemon is sometimes alive even when the web UI is dead — some KS firmware exposes an OTA-only endpoint at a separate port. Check IceRiver's firmware-download FAQ for the model-specific OTA-only recovery procedure and try pushing a firmware image directly. Long shot, but works on some firmware revisions.

Inspect the eMMC chip and PMIC visually. Phillips #2 to open chassis. Locate control board. Photograph any visible damage: scorched components, swollen capacitors, lifted IC corners, PCB discolouration. If anything looks damaged, stop — that's a hardware brick, not a firmware brick, and reflashing won't help. Ship to D-Central.

Check reset/boot button continuity with a multimeter. Some 'bricks' are a stuck reset button holding the unit in reset state because button springback failed. Multimeter on continuity, probe leads with button un-pressed — should read open. If it reads closed (electrically pressed when mechanically released), replace the button or short across it temporarily to test.

Get UART access to the control board. USB-to-TTL adapter (`CH340`, `CP2102`, or `FTDI`, `3.3 V` logic). Locate the model-specific debug header (KS0: 4-pin near Ethernet; KS3/KS3M: 4-pin on long edge; KS5L/KS5M: similar). Connect `GND-GND`, `TX (board) → RX (adapter)`, `RX (board) → TX (adapter)`. **Do not connect VCC** — board has its own power. Open `PuTTY` / `screen` at `115200 8N1`. Power on. U-Boot output should appear within 3 seconds.

Interrupt U-Boot autoboot and inspect eMMC. Press any key during the 3-second countdown to drop to the U-Boot prompt. `mmc info` should report eMMC detected with capacity (typically 4-8 GB on KS hardware). `mmc part` reads the partition table — compare against IceRiver's published partition map for your model. If `mmc info` fails, the eMMC chip is damaged and reflash will not help — Tier 4.

Reflash the rootfs partition via U-Boot. With UART link stable: `loadx` (Y-modem) or `tftpboot` (network) the recovery rootfs image into RAM. The exact addresses are model-specific — check IceRiver's firmware-download portal or the `rdugan/iceriver-oc` GitHub for documented partition layouts. Then `mmc write <RAM addr> <partition offset> <size>` to write rootfs to the correct partition. Takes 5-10 min during which UART link MUST stay connected. Power-cycle when complete.

Reflash the bootloader (U-Boot SPL) if rootfs reflash didn't fix it. Some bricks corrupt the bootloader itself — re-flashing U-Boot SPL via the BootROM's serial download protocol (varies by SoC: Allwinner = `sunxi-fel`, Rockchip = `rkdeveloptool`, etc.). Identify your KS model's SoC first, then use the matching tool. This is the deepest software-level recovery before chip-level bench work.

Verify firmware integrity post-flash. After successful reflash, run the miner for a full hour at nameplate hashrate. Check the miner log for `mmc` errors, eMMC write errors, or I/O retry warnings. A 'successful' reflash that produces I/O errors during normal operation means eMMC has marginal blocks and the brick will return — plan for control-board replacement at Tier 4.

Stop DIY and ship to D-Central when (a) `mmc info` from U-Boot fails (eMMC chip-level damage), (b) UART produces no output at all (BootROM-level fault), (c) reflash succeeds but eMMC errors return within 24 hours, (d) you see scorched components or PMIC damage, or (e) the brick happened during a power event and downstream hardware damage is suspected. Past those points, time and risk of further DIY exceed the repair cost.

D-Central bench process: UART access with stable bench power, full eMMC dump and analysis, eMMC chip desolder + external programmer reflash for irrecoverable cases, control-board swap with image transfer when chip replacement is uneconomic, full PMIC continuity testing for power-event bricks, and post-repair 24-hour burn-in at nameplate hashrate before sign-off. Western retail bench — no shipping to China, no Zeus-style trust gap.

Ship hashboards or whole unit in anti-static bags, double-boxed with ≥5 cm foam on every side. Include a printed brick history: original firmware version, brick trigger (OTA / third-party FW / power event / unknown), recovery steps already attempted, highest Tier reached. Saves D-Central 30+ minutes per unit and that savings passes back directly in the repair quote.