Antminer T21 Repair — Professional ASIC Repair by D-Central
The Bitmain Antminer T21 is the value-tier companion to the S21, delivering 190 TH/s at 19 J/TH efficiency — a substantial performer in its own right. Built on 324 BM1368 ASIC chips spread across three hashboards (108 chips per board, 12 domains of 9 chips each), the T21 shares its core architecture with the S21 but at a more accessible price point. The T21 also offers a High Energy Mode that pushes output up to 233 TH/s at 5,126–5,615W for operators with adequate power infrastructure. When these machines go down, the repair approach demands the same chip-level expertise as the S21 — because under the hood, the platform is fundamentally the same.
D-Central Technologies has been repairing ASIC miners professionally since 2016. As Canada’s Bitcoin Mining Hackers, we service every generation of Bitmain hardware. The T21’s BM1368 chip architecture, domain layout, and Amlogic A113D control board are identical to the S21 platform we already know inside out. Our technicians have the test fixtures, chip-level diagnostic tools, and parts inventory to handle any T21 fault efficiently.
Antminer T21 Specifications
| Specification | Details |
|---|---|
| Algorithm | SHA-256 (Bitcoin, Bitcoin Cash) |
| Hashrate (Normal Mode) | 190 TH/s |
| Hashrate (High Energy Mode) | 233 TH/s |
| Power Consumption (Normal) | 3,610W (±5%) |
| Power Consumption (High Energy) | 5,126–5,615W |
| Efficiency (Normal Mode) | 19 J/TH |
| ASIC Chip | BM1368 (108 chips per hashboard) |
| Total Chips | 324 (3 hashboards x 108) |
| Domain Layout | 12 domains per hashboard, 9 chips per domain |
| Domain Voltage | ~1.2V per domain |
| Control Board | Amlogic A113D (Ctrl_C76/C81) |
| Input Voltage | 380–415V AC (3-phase) |
| Cooling | Air-cooled |
| Dimensions | 400 x 212 x 290 mm |
| Weight | 17 kg |
| Operating Temperature | 5°C to 45°C |
Important note on power requirements: The T21 uses a 3-phase power input at 380–415V AC, which is different from the single-phase 220–277V used by the S21, S21 Pro, and S21 XP. This is a critical detail for installation and for diagnosing power-related issues. Many T21 problems stem from incorrect power infrastructure.
Common Antminer T21 Issues and Symptoms
The T21 shares the BM1368 chip platform with the S21, so many failure modes are similar. However, the T21’s 3-phase power requirements and High Energy Mode introduce additional failure scenarios. Here are the most frequent issues we repair:
Hashboard Failures and Low Hashrate
The T21’s hashboards contain 108 BM1368 chips organized into 12 domains of 9 chips each. When chips fail, you will see reduced hashrate, missing chips in the kernel log (e.g., “find 98 asic” instead of 108), or entire hashboards going offline. The BM1368 hashboard architecture includes 17 op-amps (SGM8304) for inter-domain signal processing — when the junction between two domains tests poorly, the op-amp is typically the first component to check. BM1368 chip variants (PA, PB, AA) are not interchangeable — matching the correct variant during replacement is critical.
Overheating and Thermal Shutdowns
The T21 triggers automatic shutdown when PCB temperature exceeds 81°C or chip temperature exceeds 98°C. In Normal Mode at 3,610W, thermal management is already demanding. In High Energy Mode (up to 5,615W), the thermal envelope is pushed significantly further. Common causes: degraded thermal paste, dust accumulation, failed or degraded fans, insufficient ambient cooling, heatsink detachment, and flux residue from prior repairs blocking heatsink-to-chip contact.
3-Phase Power and PSU Issues
Unlike the S21 which runs on standard 220–277V single-phase power, the T21 requires 380–415V 3-phase power. This is an industrial power standard not available in most residential settings. Power-related T21 failures include: incorrect voltage supply (running on single-phase when 3-phase is required), phase imbalance causing uneven hashboard performance, voltage sag under load, loose or damaged 3-phase connectors, and PSU failures from power quality issues. If your T21 is behaving erratically, the power infrastructure should be the first thing verified.
High Energy Mode Failures
The T21’s High Energy Mode pushes the miner from 190 TH/s to 233 TH/s at significantly higher power draw (5,126–5,615W). This mode stresses every component harder — chips run hotter, power delivery is pushed to its limits, and cooling must handle 40–55% more heat dissipation. Running High Energy Mode with marginal cooling, an undersized electrical circuit, or aging thermal paste dramatically accelerates component wear and failure.
Fan Failures
Fan speed warnings, abnormal fan readings on the dashboard, or fan detection failures. Motor wear, bearing degradation, cable damage, or control board fan circuitry faults. In High Energy Mode, the fans run at maximum speed continuously, which accelerates wear. Even in Normal Mode, the T21’s thermal load demands reliable fan operation around the clock.
Control Board and Firmware Issues
The T21 uses the same Amlogic A113D control board as the S21. Firmware corruption (from power interruptions — more likely with 3-phase power events), boot failures, hashboard detection problems, and network interface faults. The T21’s firmware manages both Normal and High Energy Mode profiles — corruption can cause incorrect mode selection, erratic power management, or phantom error codes.
Our Repair Process
Every Antminer T21 is repaired at our Laval, Quebec facility using a systematic workflow designed for the BM1368 platform:
1. Intake and Visual Inspection
Your T21 is logged, photographed, and visually inspected for physical damage, connector condition, heatsink integrity, dust contamination, and signs of prior repairs. We note whether the unit has been run in High Energy Mode (visible thermal stress patterns).
2. Full Diagnostic Testing
Each hashboard is tested on our BM1368 test fixture: full 108-chip enumeration, domain voltage checks across all 12 domains, op-amp signal chain validation, temperature sensor readings, and thermal imaging. The control board is tested for firmware integrity, both operating modes (Normal and High Energy), fan control, hashboard communication, and network connectivity.
3. Detailed Quote
You receive a complete diagnostic report with every fault identified, proposed repairs, itemized costs, and estimated turnaround. No work proceeds without your approval.
4. Component-Level Repair
Our technicians perform board-level repairs: BM1368 chip replacement (matching PA, PB, or AA variants exactly), op-amp (SGM8304) replacement, LDO regulator replacement, temperature sensor repair, signal trace repair, thermal paste reapplication, heatsink reattachment, and control board repair or replacement. All flux residue is thoroughly cleaned from chip surfaces before heatsink reinstallation.
5. Post-Repair Testing
Repaired hashboards are tested twice — once after repair and again after cooling — to confirm stable operation. The complete unit is then burned in on our test bench to verify sustained hashrate in Normal Mode (190 TH/s target) with stable temperatures. If the unit is destined for High Energy Mode operation, we can test at elevated power draw to confirm stability under those conditions as well.
6. Return Shipping
Your T21 is securely packaged and shipped back with full documentation of all diagnostics and repairs performed.
Repair Pricing
T21 repair costs are determined by the specific faults found during diagnostics. The T21 uses the same BM1368 chip platform as the S21, so component costs are comparable. Simple repairs cost less; complex multi-chip hashboard work costs more. You always receive an exact quote before any repair begins.
For a preliminary estimate, use our ASIC Repair Cost Estimator.
Why D-Central for Antminer T21 Repair
BM1368 platform mastery. The T21 and S21 share the same chip architecture. We service both models daily and maintain complete familiarity with the BM1368 domain layout, op-amp signal chain, and chip variant requirements. Our BM1368 chip testers and hashboard test fixtures are purpose-built for this platform.
8+ years of ASIC repair experience. D-Central has been repairing Bitcoin miners since 2016 — from S9s through every subsequent generation. We have seen every failure pattern Bitmain hardware can produce, and that depth of experience translates to faster, more accurate diagnosis.
Parts in stock. BM1368 chips (PA, PB, AA variants), SGM8304 op-amps, S75 temperature sensors, LDO regulators, Amlogic A113D control boards, fans, thermal materials, and complete hashboard assemblies — all available at our Canadian facility for fast turnaround.
Canadian repair facility. Located in Laval, Quebec, we serve miners across Canada and the US without international shipping complications. No sending your miner overseas. Call us directly at 1-855-753-9997.
Transparent pricing and warranty. Full diagnostic report, exact quote with your approval required, documented repairs, and warranty coverage on all work performed. No guesswork, no hidden charges.
Frequently Asked Questions
What is the turnaround time for a T21 repair?
Most T21 repairs are completed in 5–10 business days. Simple issues (fan replacement, firmware) take 1–2 days. Multi-chip hashboard repairs may take up to 2 weeks. We provide an estimated timeline with your diagnostic report.
Do you warranty T21 repairs?
Yes. All repairs by D-Central include a warranty covering our workmanship and the components installed. If the same fault recurs within the warranty period, we repair it again at no charge.
How do I ship my T21 for repair?
Contact us to open a repair ticket first. We will provide our Laval, Quebec shipping address. Pack the unit securely — original packaging is ideal, or use a sturdy box with foam padding. The T21 weighs 17 kg. Remove the PSU unless you suspect a power supply issue. Include a note describing the symptoms and whether you have been running Normal or High Energy Mode.
How much does a T21 repair cost?
Costs depend on the fault. Fan or firmware repairs: $50–$150. Single-chip hashboard repair: $150–$400. Multi-chip or complex board repairs: $400–$800+. We provide exact pricing after diagnostic testing. Use our ASIC Repair Cost Estimator for a preliminary figure.
Can I run my T21 on single-phase power instead of 3-phase?
The T21 is designed for 380–415V 3-phase power. Running it on single-phase power without proper conversion equipment will not work correctly and may damage the unit. If you need to run a T21 on single-phase power, you need a properly rated phase converter or a compatible single-phase PSU (if available for your T21 variant). This is a common source of T21 issues we see — incorrect power infrastructure causing erratic behavior or component damage.
Is it safe to run my T21 in High Energy Mode continuously?
High Energy Mode pushes the T21 from 190 TH/s to 233 TH/s at significantly higher power consumption (5,126–5,615W). It is designed to be operational, but the increased thermal load accelerates component wear. If you run High Energy Mode, ensure your cooling infrastructure is adequate, your power circuit can handle the draw, and your thermal paste is fresh. We see higher failure rates from T21 units that have been running High Energy Mode continuously in marginal cooling environments.
Can I attempt T21 repairs myself?
The T21 uses the same BM1368 chip architecture as the S21, with 324 chips across three hashboards, 17 op-amps per board, and non-interchangeable chip variants (PA, PB, AA). Without professional BGA rework equipment, a BM1368 chip tester, and familiarity with the domain signal chain, DIY repair risks additional damage. Basic maintenance (fan replacement, cable reseating, dust cleaning) is reasonable. Board-level chip work should be left to professionals.
Do you repair individual T21 hashboards?
Yes. You can send a single hashboard, multiple hashboards, or the complete unit. We also sell tested replacement hashboards and control boards if you prefer a board swap over a repair. Contact us for current availability.
Get Your Antminer T21 Back Online
The T21 is a workhorse miner with serious hashrate potential — 190 TH/s in Normal Mode and up to 233 TH/s in High Energy Mode. When it is down, those terahashes are going to waste. D-Central has the BM1368 expertise, the parts, and the repair infrastructure to get your T21 back to full performance.
Contact D-Central for a repair quote or call us at 1-855-753-9997.