{
    "meta": {
        "title": "D-Central — ASIC Repair Parts & Common-Failure Components",
        "description": "The 18 replaceable component classes on an Antminer hash board / control-board interface: role, package, where used, common failure mode, root cause, diagnostic signal and replacement difficulty. Bible-cited.",
        "generated": "2026-06-21T06:12:53+00:00",
        "version": "1.0",
        "license": "https://creativecommons.org/licenses/by/4.0/",
        "license_name": "CC BY 4.0",
        "source": "https://d-central.tech/asic-repair-parts/",
        "record_count": 18,
        "provenance": "D-Central Mining Bible HASHBOARD_DIAGNOSTICS.md (per-row section/line citations). Replacement-difficulty grades are an editorial synthesis of the Bible repair-technique sections + package types.",
        "disclaimer": "Component designators (U-numbers) and exact part values vary by board revision -- verify against the specific model schematic before asserting a designator. BGA/fine-pitch rework is expert-level; this catalog is a reference, not a substitute for a trained microsolder technician. The PIC supervisor exists only on S19-generation boards -- it was REMOVED from BM1368 (S21/T21) onward."
    },
    "rows": [
        {
            "id": "asic-chip",
            "component": "Mining ASIC chip (BM13xx / BM14xx)",
            "board": "Hash board",
            "role": "SHA-256 compute element; daisy-chained in voltage domains. Each chip also forwards CLK/CI/RO to the next, so one dead chip can break the whole chain.",
            "package_spec": "QFN (QFN-34 on BM1397). Generations: BM1387(S9), BM1391(S15), BM1393(S17), BM1397(S17+/e), BM1398(S19/Pro/T19/j), BM1366(S19 XP/K Pro), BM1368(S21/T21), BM1370(S21 Pro/XP/+)",
            "used_in": "All Antminer hash boards (model-specific chip)",
            "common_failure_mode": "Dead/open chip (chain breaks at chip N); shorted chip (0 chips detected + domain V collapses); low nonce rate (degraded transistors); signal-forwarding fail (cold solder on CO/CLKO/NRSTO); thermal shutdown / BGA solder crack (intermittent dropout)",
            "root_cause": "ESD, thermal runaway/power surge, transistor degradation, thermal cycling/vibration, poor thermal paste",
            "diagnostic_signal": "Chip-enumeration count per chain (PT1); domain voltage measurement; per-chip nonce count (PT3 sweep); thermal camera cold-spot for cracked BGA; probe CO/CLKO/NRSTO at chip I/O",
            "replacement_difficulty": "Expert (hot-air BGA removal + 0.4mm SAC reball + precise reflow; highest-skill repair)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 1.2 (L51-60), sec 5.1 (L432-441), sec 9.1 (L868), sec 12.3 (L1372-1376)"
        },
        {
            "id": "ldo-regulator",
            "component": "LDO regulator (per-domain low-dropout)",
            "board": "Hash board",
            "role": "Steps boosted/upstream voltage down to the precise per-domain core rail (VDD0V8 / VDD1V2 / 1.8V). One or more LDOs per domain (e.g. 3 LDOs/domain on S21).",
            "package_spec": "SOT-23 (or 4-pin model-specific); 0.8V (all models), 1.2V (S21/S21 XP), 1.8V (S19 series)",
            "used_in": "Every Antminer hash board; quantity scales with domain count",
            "common_failure_mode": "LDO short (domain voltage near zero); LDO open (domain voltage high/absent)",
            "root_cause": "Component failure / surge; cracked solder",
            "diagnostic_signal": "Multimeter on domain VDD test point: input present but output absent = LDO failure; unpowered domain-impedance check (low=short)",
            "replacement_difficulty": "Medium-High (small SOT-23 hot-air rework; identify correct rail variant)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 2 (L130-152), sec 5.2 (L447-448), sec 7.4 (L749-754), sec 9.3 (L912), sec 12.3 (L1377-1380)"
        },
        {
            "id": "boost-converter",
            "component": "Boost converter module / boost MOSFET",
            "board": "Hash board",
            "role": "Steps the 12-15V PSU input up to the intermediate boost rail (S19 ~19V, S19 Pro ~20V, S21 ~25V, S21 XP ~21V) that feeds the domain LDOs.",
            "package_spec": "Pre-built boost module PCB OR discrete boost MOSFET + inductor; 18V-class module is a common drop-in part (designators Q9/U206/U146/U202)",
            "used_in": "S19 and S21 series hash boards (boost output model-specific)",
            "common_failure_mode": "Boost circuit failure -> 0 chips, no domain voltages",
            "root_cause": "Boost MOSFET failure, inductor burn",
            "diagnostic_signal": "Measure boost output at output capacitor (S19 ~19V / S19 Pro ~20V C69 / S21 ~25V / S21 XP ~21V); near-zero input resistance = bus short",
            "replacement_difficulty": "Medium (swap pre-built module) to High (discrete MOSFET rework)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 1.3 (L67,76,86,101), sec 5.2 (L449), sec 7.4 (L739-747), sec 9.2 (L898), sec 12.3 (L1382)"
        },
        {
            "id": "mp2019-buck",
            "component": "MP2019 DC-DC buck converter",
            "board": "Hash board",
            "role": "On S21/S21 XP, the highest-numbered domains use an MP2019 buck stage (~2.0-2.5V) feeding their LDOs instead of a pure LDO chain.",
            "package_spec": "TSOT-23-8 (designators U166/U200 on S21; U146/U202 on S21 XP)",
            "used_in": "S21, S21 XP (high domains 11-12 / 12-13)",
            "common_failure_mode": "DC-DC buck failure -> high-voltage domain dead",
            "root_cause": "MP2019 (or similar) component failure",
            "diagnostic_signal": "Measure buck output (~2.0-2.5V) at the affected high domain",
            "replacement_difficulty": "High (TSOT-23-8 fine-pitch hot-air rework)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 1.3 (L88,99), sec 5.2 (L450), sec 12.3 (L1381)"
        },
        {
            "id": "power-mosfet",
            "component": "Power MOSFET (input power switch)",
            "board": "Hash board",
            "role": "Switches/passes main PSU current onto the board power bus.",
            "package_spec": "Multi-pin power MOS (gate=pin1, source=pin4, drain=pin8); exact part per board schematic",
            "used_in": "Antminer hash boards (power input stage)",
            "common_failure_mode": "Power MOS short -> board draws excessive current",
            "root_cause": "Surge, thermal",
            "diagnostic_signal": "Resistance between pins 1,4,8; short between any two pins = MOSFET failure; near-zero input-connector resistance = bus short",
            "replacement_difficulty": "Medium-High (power-package hot-air; large thermal mass)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.2 (L452), sec 6.2 (L525-530), sec 7.4 (L731-737)"
        },
        {
            "id": "power-inductor",
            "component": "Boost/buck power inductor",
            "board": "Hash board",
            "role": "Energy-storage element of the boost/buck switching stage that generates the intermediate boost rail.",
            "package_spec": "Large SMD shielded power inductor (value model-specific; not enumerated in Bible — see uncertainties)",
            "used_in": "S19/S21 boost (and S21 buck) stages",
            "common_failure_mode": "Inductor burn / open -> boost stage produces no/low output (0 chips, no domain voltages)",
            "root_cause": "Overcurrent from a failed/shorted switching MOSFET; thermal stress",
            "diagnostic_signal": "Visual: burnt/discolored inductor; boost output absent at output cap; bus short on input resistance",
            "replacement_difficulty": "Medium (large pads, high thermal mass; needs strong hot-air/preheat)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.2 (L449 'inductor burn'), sec 9.2 (L898)"
        },
        {
            "id": "filter-capacitor",
            "component": "Filter / decoupling capacitor",
            "board": "Hash board",
            "role": "Smooths domain rails (LDO filtering), decouples chip supply, and couples the CLK line.",
            "package_spec": "1uF 0402 16V X5R (decoupling); 22uF 0603 6.3V X5R (LDO filtering); 100nF 0402 (CLK coupling)",
            "used_in": "All models (large quantity per board)",
            "common_failure_mode": "Filter capacitor short -> domain voltage sags",
            "root_cause": "Capacitor dielectric breakdown",
            "diagnostic_signal": "Impedance measurement on the affected domain (sagging V + low impedance)",
            "replacement_difficulty": "Medium (small 0402/0603 SMD; identify failed cap among many)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.2 (L451), sec 9.7 (L982), sec 12.3 (L1391-1393)"
        },
        {
            "id": "signal-resistor",
            "component": "Signal-chain resistor",
            "board": "Hash board",
            "role": "Series/termination resistors on CLK, CI/BO and reset lines between domains; pull-up/pull-down on logic and I2C lines.",
            "package_spec": "33 ohm 0603 +/-1% 1/20W (signal chain); 10K 0402 +/-1% 1/16W (pull-up/down)",
            "used_in": "All models; concentrated at domain boundaries",
            "common_failure_mode": "CLK-resistor cold joint -> chain breaks at domain boundary; CI/BO resistor fault -> chain breaks mid-domain",
            "root_cause": "Cold/cracked solder, manufacturing defect, thermal cycling",
            "diagnostic_signal": "Probe CLK before/after the resistor; probe CI/BO at each chip; oscilloscope at the boundary",
            "replacement_difficulty": "Medium (tiny 0402/0603; value/placement ID is the hard part)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.3 (L460-461), sec 6.1 (L495), sec 9.7 (L982), sec 12.3 (L1389-1390)"
        },
        {
            "id": "crystal-oscillator",
            "component": "Crystal oscillator (CLK source)",
            "board": "Hash board",
            "role": "Generates the master 25MHz clock that drives the entire chip chain; without CLK no chips enumerate.",
            "package_spec": "SMD passive crystal, 25 MHz, designator Y1",
            "used_in": "All models (Y1 25MHz)",
            "common_failure_mode": "Crystal failure -> 0 chips, no CLK",
            "root_cause": "Cracked crystal, cold solder",
            "diagnostic_signal": "Oscilloscope on CLK test point (no/abnormal 25MHz waveform)",
            "replacement_difficulty": "Medium (small SMD hot-air; verify oscillation after)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 3.4 (L264), sec 5.3 (L458), sec 12.3 (L1383)"
        },
        {
            "id": "level-shifter",
            "component": "Level-shifter IC",
            "board": "Hash board",
            "role": "Translates logic signal levels across voltage-domain boundaries so CLK/CI/RO propagate down the chain (S21 adds 11; S21 XP uses 12, U1-U12).",
            "package_spec": "Small fine-pitch logic IC (designators U1, U2, ... per model)",
            "used_in": "S19 (U1,U2) and S21 family (11-12+ units)",
            "common_failure_mode": "Level-shifter failure -> partial chain stops at a domain boundary",
            "root_cause": "IC failure, voltage loss",
            "diagnostic_signal": "Signal probe at shifter input vs output (signal present in, absent out)",
            "replacement_difficulty": "High (fine-pitch IC hot-air rework)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 1.3 (L89,100), sec 3.3 (L249), sec 5.3 (L459), sec 12.1/12.2 (L1347,1364)"
        },
        {
            "id": "temp-sensor",
            "component": "Temperature sensor IC",
            "board": "Hash board",
            "role": "Reports board/chip temperature to the control board over I2C; feeds thermal protection.",
            "package_spec": "LM75A SOIC-8 I2C (S19, L9); TMP1075 SOT-563 I2C (newer); NCT218 (various). S19: U4/U6/U7/U8; S21: U5(inlet)/U7(outlet)",
            "used_in": "All models (2-4 sensors per board)",
            "common_failure_mode": "Temp sensor failure -> thermal protection trips falsely; I2C bus stuck -> multiple subsystems fail",
            "root_cause": "Sensor IC failure, I2C stuck/SDA-SCL shorted",
            "diagnostic_signal": "I2C bus scan + sensor read; oscilloscope on SDA/SCL",
            "replacement_difficulty": "Medium-High (small I2C IC; SOT-563 is very small)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 4.8 (L413), sec 5.4 (L471-472), sec 12.1 (L1344), sec 12.3 (L1384-1386)"
        },
        {
            "id": "eeprom",
            "component": "EEPROM (board identity memory)",
            "board": "Hash board",
            "role": "Stores per-board calibration/identity data the control board reads at boot over I2C; mismatched/blank EEPROM = board rejected.",
            "package_spec": "SOIC-8 I2C; S19 U5, S19 Pro U10, S21 U6 (model-specific contents)",
            "used_in": "All models",
            "common_failure_mode": "EEPROM corruption -> board not recognized; EEPROM mismatch -> mixed boards won't hash",
            "root_cause": "Write failure, I2C bus fault, wrong/cloned data",
            "diagnostic_signal": "EEPROM reader/programmer (CH341A); code-editor comparison against a known-good board",
            "replacement_difficulty": "Medium hardware swap; data side requires correct dump + reflash (CH341A / hash-board code editor)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.4 (L469-470), sec 6.7 (L674), sec 9.5 (L945), sec 12.3 (L1387)"
        },
        {
            "id": "pic-mcu",
            "component": "PIC microcontroller (S19-generation)",
            "board": "Hash board",
            "role": "Local supervisor that gates the board 3.3V/power-up handshake on S19-era boards. NOTE: removed from BM1368 generation onward (S21/T21 and later have NO PIC).",
            "package_spec": "PIC16F1704 SOIC-14; S19 U3, S19 Pro U6",
            "used_in": "S19 series only (NOT S21/S21 Pro/XP/+ — PIC removed in BM1368)",
            "common_failure_mode": "PIC failure -> 0 chips, no 3.3V output",
            "root_cause": "Programming/firmware corruption, ESD",
            "diagnostic_signal": "Measure U3/U6 pin 2 for 3.3V (absent = PIC fault); chain dead at power-up",
            "replacement_difficulty": "Medium hardware (SOIC-14) + reprogram with PICkit3 and correct firmware image",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 1.3 (L69,79), sec 5.4 (L468), sec 9.6 (L966), sec 12.2 (L1359 'No PIC' on S21), sec 12.3 (L1388)"
        },
        {
            "id": "signal-cable",
            "component": "18-pin signal cable & board connector",
            "board": "Hash board <-> Control board interface",
            "role": "Flat ribbon carrying 3.3V logic power, GND, RST, I2C (SDA/SCL), and UART TX/CI + RX/RO between control board and each hash board.",
            "package_spec": "18-pin flat ribbon; board-side connector (pinout: 1 GND, 2 VCC_3V3, 3 RST, 4 SDA, 5 SCL, 7 TX/CI, 8 RX/RO)",
            "used_in": "All S19/S21 boards",
            "common_failure_mode": "Connector damage / cable fault -> intermittent or no communication with the board",
            "root_cause": "Wear, corrosion, bent pins",
            "diagnostic_signal": "Inspect connector pins; signal-probe across the cable; swap with a known-good cable",
            "replacement_difficulty": "Low (swap ribbon) / Medium (reflow or replace board connector)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 1.1 (L45-47), sec 1.4 (L104-122), sec 5.5 (L481), sec 12.3 (L1396)"
        },
        {
            "id": "bga-solder-balls",
            "component": "BGA solder balls (reballing consumable)",
            "board": "Hash board (consumable for chip replacement)",
            "role": "Re-form the ball-grid array under a replacement ASIC during reballing/reflow.",
            "package_spec": "0.4mm lead-free Sn/Ag/Cu (SAC) solder balls",
            "used_in": "BGA reballing on all models",
            "common_failure_mode": "N/A (consumable) — wrong size/alloy or poor reflow -> bridged/open BGA joints, intermittent dropout",
            "root_cause": "Process error during reball",
            "diagnostic_signal": "Post-repair: thermal camera + chip enumeration to confirm all joints made",
            "replacement_difficulty": "Expert-process (part of the ASIC chip replacement workflow)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 8.1 (L770), sec 9.1 (L868), sec 12.3 (L1394)"
        },
        {
            "id": "thermal-paste",
            "component": "Thermal interface material",
            "board": "Hash board (consumable)",
            "role": "Conducts heat from each ASIC die into the heatsink; degraded paste = local hotspots and thermal shutdown.",
            "package_spec": "Fujipoly SPG-30B (or equivalent high-conductivity TIM)",
            "used_in": "All models",
            "common_failure_mode": "Dried/insufficient TIM -> thermal shutdown, chip intermittently drops out",
            "root_cause": "Age, heat-cure, prior poor application",
            "diagnostic_signal": "Thermal camera hotspot + elevated chip temp read; visual on disassembly",
            "replacement_difficulty": "Low (clean + reapply during routine maintenance)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.1 (L441), sec 9.8 (L995), sec 12.3 (L1395), sec 12.4 (L1404)"
        },
        {
            "id": "heatsink-clips",
            "component": "Heatsink & retention clips",
            "board": "Hash board (mechanical)",
            "role": "Dissipates ASIC heat; clips hold the heatsink in contact with the die.",
            "package_spec": "Aluminum heatsink + spring clip (model-specific)",
            "used_in": "All models",
            "common_failure_mode": "Heatsink detachment -> thermal shutdown",
            "root_cause": "Dried thermal paste, clip failure/loss",
            "diagnostic_signal": "Visual + thermal camera (detached/hot region)",
            "replacement_difficulty": "Low-Medium (mechanical; re-clip + re-paste). CAUTION: never touch black meter probe to the heatsink (short risk)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.5 (L482), sec 6.1 (L500-503), sec 6.2 (L539-540)"
        },
        {
            "id": "pcb-trace",
            "component": "PCB trace / via (board substrate)",
            "board": "Hash board (substrate)",
            "role": "Carries power and signals across the board; damaged traces open a domain or break the signal chain.",
            "package_spec": "Multilayer PCB copper (jumper-wire repair where damaged)",
            "used_in": "All models",
            "common_failure_mode": "Trace damage -> signal chain break or domain open; corrosion from liquid damage",
            "root_cause": "Physical damage, corrosion, delamination",
            "diagnostic_signal": "Visual inspection + continuity test; via integrity check under magnification",
            "replacement_difficulty": "Expert (microsoldering / jumper-wire trace repair)",
            "citation": "HASHBOARD_DIAGNOSTICS.md sec 5.5 (L480), sec 6.1 (L505-508), sec 6.2 (L532-536)"
        }
    ]
}