Identify the exact machine
A used miner’s model name is only the start of the inspection. Request the serial number, hardware variant, included power supply, firmware version, and clear photographs of the actual unit. Ask about its operating environment, repair history, modifications, and reason for sale. Keep the seller’s statements with the quote so the agreed condition is documented.
Check any claimed manufacturer warranty through the manufacturer’s own process. A valid serial lookup does not prove the seller owns the device or that every repair will be covered. Confirm the relevant warranty terms, remaining coverage, and required purchase documents. Seller-provided warranty and manufacturer warranty are different commitments.
Ask for useful operating evidence
Request a recent live demonstration or dated test that ties the serial-numbered unit to its dashboard. Review sustained hashrate, detected hashboards, temperatures, fan status, rejected shares, and any errors. A brief screenshot of a peak number is weak evidence of stable operation. Ask what power mode and ambient conditions were used during the test.
Inspect visible corrosion, damaged connectors, loose parts, missing labels, and signs of unsuitable repairs. Do not open powered equipment or attempt electrical repair during an inspection. If you cannot judge its condition, arrange an independent qualified inspection. A cleaned exterior cannot tell you the full condition of internal electronics.
Agree the handover before payment
Calculate the delivered cost, including shipping, duties where relevant, likely repairs, installation, and any needed accessories. Get return conditions, testing period, packaging responsibility, and payment terms in writing. After delivery, compare the device with the agreed identity and condition before startup. Obtain compatible firmware only through the official source and follow its update procedure.
- Keep the listing, test evidence, invoice, and shipping records.
- Change administrative credentials and verify pool and payout settings.
- Do not let a low purchase price replace compatibility and cost checks.