Avalon – PSU Incompatible Model
Incompatible PSU detected on Avalon chassis — non-Canaan or wrong-generation PSU will not handshake with the MM control board over IIC; attempting to force or splice damages hashboard PMICs.
Warning — Should be addressed soon
Symptoms
- PSU plug will not physically seat into the Avalon MM control-board input without excessive force
- Pin count on the PSU output cable does not match the Avalon MM input (Canaan: single proprietary connector; Bitmain: 6 x 6-pin PCIe; MicroBT: 10-pin AMP-style)
- PSU output is 12 V nominal (Bitmain / MicroBT) rather than the split ~6 V / ~12 V Canaan AUC3-integrated PSUs deliver
- Miner boots partially — fans spin, AUC3 LED initializes — then hard-shuts down within 10-60 seconds with no log line beyond `power down` or `mm_poweroff`
- CGMiner API `stats` on TCP port 4028 shows all `PS[0..N]` values as zero — MM cannot read any PSU status over IIC
- Red LED sustained on the AUC3 with no corresponding `ECHU` or `ECMM` fault code
- PSU sticker reads `Antminer`, `APW3`, `APW9`, `APW12`, `Whatsminer`, `P21`, `P222C`, or any non-Canaan brand string
- Miner arrived from a liquidation or grey-market seller without its original PSU, and a mismatched-brand PSU was substituted
- Smell of burnt electrolytic or hot PCB coming from around the PSU-to-MM connector after a brief power-up attempt
- Canaan native PSU was replaced with a generic 12 V server PSU (HP common-slot, Delta, Emerson) and rewired
- CGMiner log contains `CODE_MMCRCFAILED` repeatedly on boot — MM is attempting IIC to a PSU that cannot respond on the Canaan protocol
- Avalon Q / Nano 3: unit powers on but refuses to start mining because onboard PSU detection returns an unexpected ID string
Step-by-Step Fix
Read the PSU sticker. Record brand, model, wattage, output voltage. Confirm it says `Canaan` or `Avalon` or a known Canaan-OEM designator (`APW31222a`, `APW41222`, P2-prefixed model codes). If it says Bitmain, APW3/APW9/APW12, Antminer, Whatsminer, P21, P221, or any non-Canaan brand, stop here — you have an incompatible PSU. Order the correct Canaan-spec replacement from D-Central or a trusted supplier. Do not power on again.
Read the Avalon chassis sticker. Match the exact model (A1066, A1166 Pro, A1246, A1346, A1366, A1466, Q, Nano 3) to the Canaan-spec PSU compatibility table in Tier 2 Step 6. Within-family (same generation) PSUs are generally swappable; cross-generation is not guaranteed due to firmware PSU-ID whitelisting on A1346/A1366/A1466/Q/Nano 3.
Cold-power-cycle the miner. Unplug from wall for 5 full minutes, then re-plug. Canaan MM firmware on several generations has a documented cold-start handshake that fails from warm state but succeeds from fully-discharged cold. If the miner comes up cleanly, the PSU is fine — log this and move on.
Verify wall outlet voltage. Avalon-class miners want 220-240 V input. A 110-120 V North American residential outlet doubles the amp draw, saturates the breaker, and trips `OC_Pri` at full load. The symptom mimics incompatible PSU; the fix is a proper 240 V circuit. Measure with a multimeter at the outlet under load, not at idle.
Check firmware version against hardware revision at `avalonminer.org/firmware-document/`. If a previous owner flashed firmware for a different Avalon model, the firmware can refuse to recognize an otherwise-correct PSU. Re-flash the exact firmware for the hardware revision on the chassis build-board label.
Cross-reference the Canaan-spec PSU compatibility table (see draft text). A721-841 classes use Canaan 1.2-1.5 kW units; A1026-A1066 use 2.5 kW; A1146/A1166/A1166 Pro/A1166S/A1246 use `APW31222a` 3300 W split-rail; A1346/A1366/A1466 use `APW41222`-class 3500 W; Avalon Q uses the Q-specific unit; Nano 3 uses USB-C PD 100 W+. Verify the exact part number against your chassis sticker before purchase.
Bench-test the PSU output before install. Disconnect from the miner. Jumper the PSU-enable pin per its datasheet. Measure each output rail under no load with a multimeter on DC. Compare to expected rail voltages for that PSU family. Out-of-spec = PSU internally failed, replace. In-spec but miner still rejects = IIC handshake issue (Step 8) or model whitelist lockout (Step 5).
Verify IIC bus pins on the PSU output connector. Canaan PSUs carry SDA/SCL on dedicated pins in the main output. With the PSU off, use a multimeter in continuity mode to confirm the IIC pins on the PSU match the expected pinout for the MM input. A rewired PSU from a previous owner often has SDA/SCL swapped or missing — no IIC means no handshake, and the `PS` array reads all zeros.
Swap PSU with a known-good, confirmed-correct Canaan-spec unit. Definitive test. If swap to a known-good PSU clears the symptom, your original PSU is incompatible or failed. If symptom persists with a known-good PSU, the MM control board is at fault — pivot to the Avalon AUC Controller Failure page.
Check line-input voltage at the wall under load. On 220-240 V North American split-phase, expect 235-245 V. On 208 V commercial, expect 202-212 V. Line voltage below 210 V plus a marginal PSU plus a rig at nameplate draw produces false-positive `incompatible PSU` symptoms (`UV_out`, random shutdowns). Not a PSU problem — a circuit problem. Upgrade the feed.
Bench-test PSU under programmable electronic load at 80% of nameplate. Verify each output rail holds within +/-3% across the full load range. Canaan OEM PSUs pass this spec; tired units sag under real hashboard load even if they pass at no-load. This is the Tier 3 reality check before concluding `the PSU is fine`.
Scope the IIC bus on boot. 2-channel oscilloscope (Rigol DS1054Z or Siglent equivalent) on SDA and SCL pins at the MM input. Power on and capture the first 30 seconds. Healthy boot shows MM sending `0x50`-family IIC read requests and PSU ACKing with `PS` byte stream. Silence from PSU = PSU does not speak the Canaan protocol (incompatible) or is dead. Most diagnostic step when PSU brand checks out but model is ambiguous.
Flash the correct firmware for the hardware revision. Verify hardware table at `avalonminer.org/firmware-document/` against the chassis build-board label. Flash exact matching firmware. If the PSU itself has an MCU (A13xx-class), re-flash it too. Firmware mismatch between MM and PSU is a real failure mode on the A1346/A1366/A1466 family.
Rebuild a spliced PSU harness to factory spec. If a previous owner cut and re-crimped the PSU harness, rebuild using Canaan-OEM-equivalent wire gauge (10 AWG on main rails, 22 AWG on IIC), matching pin crimps, and a fresh Canaan-spec connector. Verify pinout against the Canaan A1246 manual pinout diagram before first power-on. Document every pin. Budget a weekend.
Replace failed electrolytic capacitors in the PSU. If the PSU is a genuine Canaan unit that used to work and now sags under load, bulging electrolytics on the primary or secondary side are the most common internal failure. Replace with 105 C low-ESR equivalents of matching voltage and capacitance. Solder-iron + capacitor-meter work, not hot-air reflow.
Stop DIY: if Tier 3 firmware flash + confirmed-correct Canaan PSU + known-good cables still does not bring the miner up cleanly, you are looking at MM control-board damage, hashboard PMIC damage from a prior wrong-PSU event, or a firmware whitelist lockout only Canaan can unlock. Book a D-Central ASIC Repair slot.
D-Central bench process: Canaan-OEM PSU stock on hand across all current Avalon generations; programmable DC load for pre-install verification; scope capture of IIC bus at boot; MM firmware re-flash with model-matched firmware; hashboard PMIC diagnostic if a prior wrong-PSU event is suspected; 24-hour nameplate burn-in post-repair.
Ship the whole rig, not just the suspect PSU, if the hashboards were ever powered on with an incompatible PSU. We need to check hashboard PMICs for blown MOSFETs that may not have failed catastrophically yet but will under continued load. Pack the chassis in anti-static wrap, double-box with at least 5 cm of foam on every side, include a note on PSU swap history. Saves diagnostic time and your repair cost.
When to Seek Professional Repair
If the steps above do not resolve the issue, or if you are not comfortable performing these repairs yourself, professional service is recommended. Attempting advanced repairs without proper equipment can cause further damage.
Related Error Codes
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