Whatsminer M30S+ – Voltage Domain Failure

Hard power-cycle at the PDU for a full 60 seconds: breaker off, capacitors drain, breaker on. A soft reboot can carry stale Error 540 / 550 / 560 state across; a true cold start clears it and clears any transient post-firmware-update glitches. Watch the first 15 minutes of BTMiner log via SSH or the web UI log tab. Clears about 4% of VDOM_FAIL-flagged tickets in D-Central's M30-series queue with zero tools and zero risk.

Pull the API baseline. `echo -n '{"cmd":"summary"}' | nc <miner-ip> 4028 > summary.txt`, then repeat for `{"cmd":"devs"}` and `{"cmd":"devdetails"}`. Save all three to a file named `<miner-serial>-vdom-baseline-<date>.txt`. This is the first artifact D-Central's bench asks for if escalation is needed - chip count delta versus nameplate, contiguous frequency-zero block location, and per-chain MHS averages tell us 80% of what we need before the unit lands.

Sanity-check firmware variant against hardware variant. M30S+ ships in air-cool only; no hydro variant exists for this model. Confirm the BTMiner build loaded matches air-cool M30S+ at support.whatsminer.com. Wrong firmware family produces structurally wrong per-domain tuning and can present exactly like a PMIC failure when the silicon is fine. Ten-second check that occasionally is the entire fix.

Reset MinerTool reporting and re-fetch. Some MinerTool builds cache stale 540 / 550 / 560 flags and surface them past resolution. Disconnect the miner from MinerTool, restart MinerTool, reconnect. If the banner clears, the live state was already healthy and MinerTool was lying about the fault.

Power off at PDU 5 minutes. Reseat the flagged hashboard fully. Free the fin stack with Torx T8 or T10, label the slot with masking tape, remove the board, inspect the adapter-plate connector and 12 V copper bus bar for oxidation, black tarnish, bent pins, missing or backed-out retention screws. Wipe every contact with 99% IPA on a lint-free wipe. Reseat firmly until the latch and every retention screw is fully engaged with even torque. Power on, hash 15 minutes, re-pull `devs.txt`. Stock 'reseat the board' advice does work when contact resistance on the 12 V bus was starving the domain.

Hashboard swap between slots. Power off. Move the flagged board to a different slot, move that slot's board into the original. Power on, 15 minutes, re-pull `devs.txt`. If the cold block follows the board to its new slot, the board is the problem. If the cold block stays in the original slot regardless of which board is in it, the control-board / cable / slot-specific power path is the problem. Highest-information 30-minute diagnostic without a multimeter.

Inspect and replace data ribbon. Power off. Unplug the data ribbon between control board and the flagged hashboard. Inspect both ends for bent pins, cracked insulation, burn marks, oxidation. Replace with a known-good spare from d-central.tech/product-category/replacement-parts/. Reseat firmly, retest. Damaged ribbons can produce phantom 540 / 550 errors that intermittently move between slots as the cable flexes.

Verify PSU output rail under load. Multimeter on DC, probe at the PSU-to-hashboard 12 V connector with the miner hashing at full nameplate (3344 W typical for M30S+ at stock). Expect 12 V ±200 mV. More than 200 mV under nominal sustained = PSU tired or the mains circuit is undersized. A sagging 12 V bus mimics a domain failure on the first board in the supply chain. Swap PSU with a known-good unit before declaring board-level fault. M30S+ runs on 220-277 V mains; line voltage logger on the input, alert below 215 V sustained.

Reset to factory and run a clean autotune cycle. Via MinerTool or web UI: factory-reset, reflash the exact current stable BTMiner build for M30S+ air-cool, boot, let the autotuner run a full cycle (20-40 minutes). Pull `summary.txt`. Autotune over-correction - cached transient under-voltage from a prior power event being treated as the new ceiling for one board - clears here. If imbalance returns within 30 minutes of clean autotune completion, autotune is not the cause.

Compressor-blow the fin stack and hashboard. Miner off, real shop air compressor at 80-90 PSI from exhaust side back through the intake. A dust layer trapped under the heatsink causes a specific chip cluster to throttle on temperature and present as 560 rather than as a temperature-sensor fault. Zero-cost step worth doing during any board pull regardless of root cause.

Map the per-chip frequency for the suspect board and locate the cold cluster. From `{"cmd":"devs"}` on port 4028, list every chip's `Frequency` for the suspect board. Identify the contiguous block of chips at zero or significantly reduced frequency. Walk that block to the corresponding physical chip positions on the board (community teardown maps from bitcointalk.org and thanosmining.com align chip enumeration order to PCB position). The block you've identified is the failed domain.

Thermal-camera survey at full hash. FLIR ONE Pro, FLIR C5, or any sub-$500 thermal cam. Run the miner under full load for 10 minutes, image the suspect board through the heatsink's open ends. A domain failure shows as a cold rectangle on the otherwise hot heatsink - chips in the failed domain produce no heat. Cross-reference the cold rectangle against the per-chip frequency map. They should overlay exactly. Photograph for your records and to send with the board if you escalate to D-Central.

Visual inspection of the failed domain. Pull the heatsink on the suspect board. With a 10x loupe walk the failed domain's PMIC, MOSFETs, inductors, electrolytic caps, and MLCCs. Bulging or leaking electrolytics, scorched MOSFET packages, cracked inductor cores, lifted PMIC pads, blackened resistors - photograph anything you find before you touch it. About 60% of domain failures show visible damage on inspection; the other 40% are PMIC die failures with no visible cue.

Per-domain voltage measurement under load. Multimeter on DC, common ground on the board frame. Probe each domain's Vcore output stage (after the inductor, before the chip chain) with the miner hashing at full power. Reference your model's teardown thread on bitcointalk.org for probe points. Healthy domains hold Vcore within ±20 mV of each other. A single domain reading 30-100 mV below the others is the failed PMIC. A domain reading 0 V is a fully dead PMIC, MOSFET, or inductor. Measure also the inductor across each phase - a cracked or shorted inductor reads as a sagging or zero domain.

Component-level repair on the failed domain. Hot-air rework station, solder paste, flux, matching-spec replacement parts. Sequence: discharge any retained capacitor charge, desolder the failed component (cap / MOSFET / inductor / PMIC), clean the pads with solder wick + flux + IPA, install the replacement with matching solder paste and proper hot-air profile (preheat 150 C, top-side 310-330 C for 30-45 s depending on package mass), inspect for bridges with the loupe, clean residual flux. Reapply Arctic MX-6 or Kryonaut, reassemble the fin stack with even torque. Boot, run a full autotune cycle, re-pull `devs.txt`. With skills + parts, $25-$75 in components plus 2-3 hours of bench time. Without, ship the board to D-Central.

Stop DIY and book a D-Central ASIC Repair slot when any is true: two or more voltage domains have failed on the same board; reflowed or replaced PMIC fails again within 30 days; visible PCB-level damage (lifted traces, cracked substrate, burnt copper); slot-specific failure persists after a known-good control-board and ribbon swap; per-chip frequency map shows multi-domain failure across more than 25% of the board's chips; or Tiers 1-3 are complete and the cold block is still cold. Book at d-central.tech/services/asic-repair/. Typical turnaround 5-10 business days from Canada / US / international.

D-Central bench process on a VDOM_FAIL case: test-fixture boot with programmable load and current-limited supply, per-domain ripple measurement and Vout characterization under steady load, thermal-camera survey at full hash, UART chain-integrity trace via logic analyzer to confirm whether failed chips are silent or simply under-powered. PMIC swap with matching-spec part (we keep stock of the common M30-series PMIC controllers, MOSFETs, and inductors). Cap and MLCC replacement on any visible drift. Full reflow on the affected domain. Post-repair 24-hour burn-in at nameplate before the board ships back. Original serial number stays - we don't blanket-swap boards.

Ship safely. Hashboard in anti-static bag, double-boxed with at least 5 cm of foam on every side. Include a physical note inside with: full `summary.txt`, `devs.txt`, and `devdetails.txt` dumps from Step 2; thermal-camera images of the cold cluster from Step 12; BTMiner firmware version + build date; installation date; last paste-refresh date; ambient at install; and the Tier 1-3 steps you already completed. Every minute the bench spends reconstructing fault history adds to the repair bill. A documented ship-in saves real dollars and real turnaround time.

Decision point when the repair quote exceeds 60% of a refurb hashboard's price: take the refurb. D-Central carries graded refurb M30S+ hashboards in inventory. The economics favour replace over repair past a certain damage threshold (typically when more than 25% of a board's chips are silicon-dying, two or more domains have failed, or the PCB itself has visible damage). Original boards ship to D-Central's R&D stream for component salvage, supporting the next generation of Mining Hacker parts inventory.