Power Supply Failure Fix — Antminer PSU Not Detected Troubleshooting Guide

What This Error Means

The “Power Supply Failure” error — also shown as “PSU not detected,” “No power supply found,” “Voltage output error,” or the miner simply failing to start — means the Antminer cannot establish communication with the APW power supply or is not receiving adequate power. The control board communicates with the PSU to manage voltage regulation and power delivery to the hashboards. When this handshake fails, the miner cannot operate.

This error can range from a simple connection issue to a completely dead power supply. Since the APW series PSUs deliver 2,000-3,600+ watts at high amperage, power delivery failures are both common and potentially dangerous if caused by damaged cables or connectors.

Common Causes

• Loose power cable connections — The 6-pin PCIe-style connectors between the PSU and hashboards or control board are not fully seated. Vibration and heat cycling can loosen these over time.
• Tripped circuit breaker or insufficient electrical circuit — The wall circuit cannot supply enough current for the miner and PSU. Most full-size ASIC miners require a dedicated 20A (240V) or 15A (240V) circuit.
• Failed PSU — The APW power supply has failed internally. Capacitor degradation, fan failure causing internal overheating, or component failure can kill the PSU.
• Damaged power cable — A frayed, melted, or internally broken power cable between the PSU and miner. High-current connections generate heat, and poor-quality or damaged cables can fail.
• Incorrect input voltage — The PSU is connected to 120V when it requires 240V (or vice versa for the specific model configuration). Most APW PSUs designed for full-size Antminers require 220-240V input.
• Power cord or outlet issue — The C13/C14 power cord connecting the PSU to the wall is damaged, or the outlet itself is faulty.

Step-by-Step Fix

Safety first: ASIC power supplies carry lethal voltages internally. Never open a PSU case. Always disconnect from wall power before inspecting connections. Use a multimeter to verify power is off before touching connectors.

Step 1: Verify Wall Power

Confirm the electrical outlet is providing power. Plug in another device (a lamp or phone charger) to verify the outlet works. Check your circuit breaker panel — ASIC miners can trip breakers, especially on shared circuits. If the breaker has tripped, reset it, but investigate whether your circuit is adequately rated for your miner’s power draw.

Step 2: Check Input Voltage

Use a multimeter to measure the voltage at the outlet. In North America, a 240V circuit should read 220-245V AC. A 120V circuit should read 110-125V AC. If you are running a miner that requires 240V on a 120V circuit, the PSU will not function. Most APW7, APW9, and APW12 models require 220-240V input for full-power operation.

Step 3: Inspect All Power Cable Connections

Disconnect all power cables from both the PSU and the miner. Inspect every connector for signs of melting, discoloration, burn marks, or bent pins. Firmly reconnect each cable. On the miner side, ensure all hashboard power connectors and the control board power connector are fully seated. On the PSU side, ensure the output connectors are fully engaged.

Step 4: Check the PSU LED or Status Indicator

Most APW power supplies have a green LED that indicates normal operation. When plugged in and powered on: a solid green light means the PSU is outputting power normally, a blinking light may indicate a fault condition, and no light means the PSU is not receiving input power or has failed internally.

Step 5: Test with a Different Power Cord

Replace the C13/C14 power cord between the PSU and the wall. These cords can fail internally, especially at the connector ends. Use a cord rated for the full amperage of your PSU — typically 15A minimum for most ASIC setups.

Step 6: Test PSU Output Voltage

If you have a multimeter, measure the PSU output voltage at the connector. Disconnect the PSU from the miner and use a paperclip or jumper wire to short the green (PS_ON) wire to any black (ground) wire on the main connector to activate the PSU without a miner attached. Measure the output — it should match the rated voltage for your PSU model (typically 12-14V DC for older models, variable for newer ones). If there is no output, the PSU is dead.

Step 7: Try a Known-Good PSU

If possible, test with another compatible PSU. This is the definitive test. If the miner works with a different PSU, your original PSU has failed and needs replacement.

Advanced Diagnosis

PSU ripple testing: Even if the PSU outputs the correct voltage, excessive ripple (AC noise on the DC output) can cause instability. This requires an oscilloscope to measure. Ripple above 100mV peak-to-peak can cause erratic miner behavior.

Load testing: A PSU that works under light load but fails under the full load of three hashboards may have degraded capacitors. If the miner starts but crashes when all chains begin hashing, this points to a PSU that cannot sustain its rated wattage.

Connector resistance testing: Measure the resistance across power connectors with the system unplugged. High resistance at any connector point indicates corrosion or damage that will cause voltage drop under load and potentially overheating.

When to Get Professional Help

Seek professional ASIC repair if:

• The PSU shows signs of physical damage (bulging, leaking, burning smell) — do not continue using it
• Melted or discolored connectors on the miner side — the miner board may need connector replacement
• The miner does not start with a known-good PSU — the control board power circuit may be damaged
• You need to verify whether the issue is the PSU or the miner before purchasing a replacement

D-Central Technologies diagnoses PSU and power delivery issues on all Antminer models. We carry replacement APW power supplies and perform connector repair and board-level power circuit repair. Submit a repair request here

Affected Models

PSU issues affect all Antminer models. The APW7 (used with S9, T9, L3+) is known for capacitor degradation after 3-4 years. The APW9 and APW12 (used with S19 series) are generally more reliable but can still fail. S17 and T17 models have documented issues with power connector overheating due to the high current draw of the hashboards.

Related Error Codes

• Voltage Error / Voltage Too Low — A degrading PSU may deliver below-spec voltage before failing completely
• Chain X Only / Missing Hashboard — Insufficient power delivery can prevent individual hashboards from initializing
• Fan Speed Error — PSU issues can affect fan power delivery
• Low Hashrate — A PSU struggling under load causes hashrate instability
• Whatsminer Power Off — The equivalent PSU issue on Whatsminer hardware

Frequently Asked Questions