Antminer – 220V to 110V Wrong Connection

Kill power at the breaker — not a soft shutdown. Throw the breaker at the panel. Verify the miner is dark at the front panel. Do not try to gracefully shut down a miner that is currently browning out on wrong voltage; every PSU retry pulls inrush current and accumulates damage. The breaker is the only real off-switch here. Leave unplugged until diagnostics are complete.

Identify the outlet type and circuit rating. Walk to the receptacle: NEMA 5-15 / 5-20 = standard 120 V household; NEMA 6-15 / 6-20 / L6-20 / L6-30 / 14-30 / 14-50 = 240 V. Then walk to the panel, find the breaker, and note whether it is single-pole (120 V) or double-pole / ganged (240 V split-phase). Trust the breaker, not the receptacle — a 240 V-labeled outlet wired to a 120 V breaker is a common install mistake.

Multimeter verification at the outlet. Set meter to AC volts. Probe hot-to-hot on a 240 V receptacle; hot-to-neutral on 120 V. Expect 235-245 V on 240 V split-phase, 202-212 V on 208 V commercial three-phase, 118-124 V on 120 V household. If you read 115-125 V across the hot pins on what should be a 240 V outlet, the outlet is mis-wired or single-phase 120 V. Do not re-energize. Proceed to Step 6.

Trace the cord path for sneaky adapters. C14 / C19 extension cords, cheap AliExpress 240-to-120 pigtails, generator-cable reducers, and multi-receptacle splitters can all demote a 240 V circuit silently. Unplug every adapter in the path. Re-measure AC volts at the PSU's own input connector with a multimeter to confirm what the PSU is actually seeing. If the reading at the PSU inlet differs from the outlet reading, the cord path is lying — discard the adapters.

Inspect the PSU for physical damage before re-energizing. Smell: electronics, hot PCB, ozone. Visual (through the vent, held up to bright light): bulged or leaking electrolytic caps, burn marks or discoloration near the AC inlet. Audio: shake gently — loose rattling means something has detached from the PCB. Any positive on smell / visible damage / rattle = the mis-voltage event cooked something internal; do not re-energize; skip to Tier 4 (ship to D-Central).

Install a proper dedicated 240 V circuit if you don't already have one. Hire a licensed electrician (or pull a permit yourself where permitted). Spec: dedicated breaker sized to the miner — 20 A / 240 V for S19 / S19 Pro / S19 XP class, 30 A for S21 class. Wire gauge 12 AWG minimum for 20 A, 10 AWG minimum for 30 A. Install a real NEMA receptacle (L6-20, L6-30, 14-30, or 14-50). 'Dedicated' means only the miner on that breaker — no dryer, no EV charger, no other loads.

Measure line voltage under load, not at idle. Once the miner is running on the confirmed 240 V circuit, plug in a voltage logger (Shelly EM / Emporia Vue) or a data-hold multimeter. Expect 230 V+ sustained on 240 V split-phase, 200 V+ sustained on 208 V commercial. If line voltage sags below those thresholds during peak load, the circuit is undersized; upgrade breaker/wire or move the miner to a larger feed. Sag under load mimics a mis-voltage event in the logs.

Verify PSU-to-miner compatibility against Bitmain's published matrix (support.bitmain.com/hc/en-us/articles/15909673875993). Common pitfalls: APW3++ paired with S19 (tops out at ~1800 W, S19 needs 3250 W); APW9 paired with S21 (trips OCP under S21 load); APW12-12/15 on an S21 (wrong output window — S21 needs APW17 / APW171215a). Wrong PSU model plus correct voltage input still yields PSU_ERR. Cross-check the sticker on your brick against the Bitmain table.

Swap in a known-good PSU of the correct model. Borrow from another miner, pull from a retired rig, or buy a salvage-grade unit from D-Central's parts inventory. If the substitute boots clean on the confirmed 240 V circuit and the miner hashes at nameplate, the original is damaged — budget for repair or replacement. If the substitute ALSO fails, the problem has moved past the PSU into the control board or hashboard PMICs; jump to Tier 3 / Tier 4.

Install whole-circuit voltage monitoring and surge protection. Type-2 SPD at the main panel plus Type-3 at the miner outlet. A voltage-monitoring outlet or whole-home energy monitor (Kill-A-Watt EZ for spot checks, Shelly EM / Emporia Vue for continuous logging). Log 24-48 h — anything outside 225-250 V on split-phase or 195-218 V on commercial three-phase needs to be fixed at the panel, not worked around at the miner.

PSU teardown and bulk-cap audit (advanced only). APW9 / APW12 / APW17 primary bulk caps retain 400 V+ for minutes after unplug — bleed through a 10 kΩ / 10 W resistor to ground before touching anything inside. ESR-meter the primary electrolytics; any cap above ~3× spec'd ESR is drifted. Typical mis-voltage casualties: primary bulk electrolytic on the HV rail, PFC MOSFET, occasionally the high-side gate-drive opto. If any of those words aren't comfortable, stop and send the PSU to D-Central.

Replace failed components with proper parts. Bulk caps: match voltage rating (typically 450 V on APW primary), capacitance, and 105 °C / 10,000 h minimum life grade. PFC MOSFET: genuine part from a reputable source; counterfeit MOSFETs are how you end up back in this fix in six months. Re-paste the MOSFET heatsink with proper thermal pad or paste + mica. Reflow bridges/diodes only with a hot-air station and a temperature profile you trust.

Post-repair load test before reinstalling. Dummy-load the repaired PSU at roughly nameplate wattage (resistor bank, or a retired hashboard wired as test load). Watch rail voltage and PSU case temp for 30 min. Rail stable within spec, case under 55 °C at the vent, fan RPM appropriate = safe to reinstall. Never plug a bench-repaired PSU directly back onto a production miner without the load test — the whole point of Tier 3 is not repeating the failure in production.

Flash DCENT_OS for post-recovery hashboard audit. After the PSU is confirmed clean and the miner is running on a proper 240 V circuit, flash DCENT_OS (D-Central's own open-source Antminer firmware) for per-chip HW% and per-domain voltage visibility. Run a 20 min soak. Any chip position reporting elevated HW% or 0% output means the mis-voltage event reached the hashboards — voltage-domain PMIC damage. Alternatives: Braiins OS+, LuxOS, Vnish; DCENT_OS is the Mining Hacker default, open-source, no licensing.

Document the incident for warranty / liability / insurance. Photograph the mis-wired outlet with a meter attached, the PSU damage (external and internal if opened), and the kern.log showing ERROR_POWER_LOST entries. If an electrician mis-wired the circuit, or a reseller shipped the wrong cord kit, that's their liability — the paper trail matters. D-Central has had customers recover thousands of dollars on installer liability with proper documentation.

Tier 4 stop-and-ship triggers. Stop DIY immediately if: visible cap bulging / leaking / burn marks on the PSU PCB; electronics or ozone smell from the PSU; the miner shows hashboard damage after the mis-voltage event (chain find 0 ASIC, persistent HW% spikes); a second correct-model PSU also fails on the confirmed 240 V circuit; or you aren't comfortable discharging a 450 V bulk cap. Book a D-Central ASIC/PSU repair slot — d-central.tech/services/asic-repair/.

D-Central bench process. APW test fixture with a programmable AC source (we can replay the exact mis-voltage event that killed your PSU to confirm failure mode), full component-level audit of caps / MOSFETs / diodes / optos / control IC, replacement parts sourced in Canada (no AliExpress counterfeits), 24 h nameplate-load burn-in before return. If hashboards also took a hit, voltage-domain PMIC replacement and per-domain reflow on the same repair ticket.

Ship safely. Disconnect PSU from the miner. Tape the AC inlet shut to protect the pins in transit. Anti-static bag around the PSU. Double-box with ≥5 cm foam on every side. If hashboards are also being sent, anti-static bag each one, double-box separately from the PSU. Include a written note: observed mis-voltage event, measured mains voltage, approximate duration on wrong voltage, symptoms after moving to the correct voltage, and your contact details. Good notes = less bench time = lower cost.