Used Bitcoin ASIC: Where to Buy Without Getting Scammed

Where to find

The used Bitcoin ASIC market organizes into four channels, ranked here from most to least reliable.

1. Specialized resellers. European and US distributors selling refurbished machines with burn-in and a short warranty:

• asicminer.fr, France, regular stock of S19, S19j Pro+, M30S, and M50, with a 30 to 60 day warranty;
• happymining.fr, France, a similar lineup with a 30-day warranty;
• mineshop.eu, EU-wide coverage, often at lower prices;
• ECOS.am, Armenia with EU shipping, high volumes, specialized in end-of-cycle liquidation;
• BT-Miners, US market, with occasional international shipping.

This is the safest path for a non-expert buyer. The premium over the open market runs 10 to 15 %, and it pays for verification and warranty.

2. General marketplaces. eBay and Rakuten list ASICs from both private and professional sellers. Professional sellers are generally reliable, private ones need filtering. The platform's buyer protection is your only recourse, and it does not cover wear.

3. Open classifieds. Craigslist and Leboncoin are open markets with widely variable prices. The risk of error or outright scam is high, and an on-site burn-in before payment is not negotiable. For a first purchase, avoid this channel.

4. Specialized Telegram and Discord groups. These give access to operator liquidations, typically after a halving or at the end of a hosting contract. Prices are the best on the market, but everything rests on a trust network. Always require a remote burn-in, with interface access, before any transfer of funds.

Five classic traps

1. Hidden dead hashboards. The machine boots and firmware reports near-nominal hashrate, while one or two of three hashboards are out of service. Detection: on Bitmain, the monitoring screen lists active chips per board. On MicroBT, firmware shows temperature per board, and a board at 0 °C is a dead board.

2. A power supply at the end of its life. The PSU holds five minutes on the bench, then fails after two hours under load. Detection: a minimum 24-hour burn-in, with output voltage measured during the test.

3. A machine that has been through water. Specific to hydro models or units pulled from a flooded farm. Internal corrosion progresses and failure arrives within three to twelve months. Detection: visual interior inspection, looking for oxidation on connectors and lugs.

4. A rigged burn-in. The seller runs the machine at 80 % of nominal frequency so it looks stable, when it crashes at full load. Detection: insist on a test at stock nominal frequency, on unmodified manufacturer firmware.

5. An altered serial number. A scratched or repainted serial signals a stolen machine or one from a flagged lot. Refuse the purchase without negotiating on price.

Test before payment

Verify the firmware. It must be stock, Bitmain or MicroBT. If a third-party image is installed, ask for a return to manufacturer firmware before testing. A refusal is reason enough to stop there.

Run it for 24 hours. At nominal load, hashrate must stay stable within ±3 % for the whole period, with no accumulating errors, and every hashboard must stay inside its normal thermal range.

Measure with a wattmeter. Placed between socket and machine, it should confirm wall draw within ±5 % of specification. A gap above 10 % signals a PSU or hashboard problem.

Inspect over SSH. For a technical buyer, connecting to stock firmware allows reading error logs, per-board temperatures, and the hash error counter. Any non-zero counter over an hour of stable running deserves an explanation.

Photograph the serial number and have it verified with the manufacturer, through Bitmain support or a MicroBT European partner, to confirm the production date and the absence of any flag.

Shipping and customs

Buying locally or inside your own customs union means no duties, with VAT already included, for delivery in three to seven days.

Buying from outside it adds three lines:

• VAT on the declared value plus shipping, 20 % in France for example;
• customs duties, around 2 % in the computing equipment category;
• broker fees from the carrier, $30 to $85 at UPS or DHL.

On a machine declared at $4,200, that means roughly $840 of VAT, $84 of duties, and $30 to $85 of brokerage, so a total surcharge of $955 to $1,010 before shipping. That is six to eight months of margin on an entry-tier machine, so it belongs in the calculation before comparing a US price to a European one.

Some specialized resellers handle group imports with customs cleared inside the listed price, which often works out cheaper than an individual import for small quantities.

Maximum price to pay

Reference price per terahash on the 2026 used market:

Model	Condition	Max reasonable $/TH
Antminer S19j Pro+	refurbished, burn-in done	$10 to $13/TH
Whatsminer M30S++	refurbished, over 18 months of use	$8 to $11/TH
Whatsminer M50	refurbished, under 12 months of use	$14 to $17/TH
Whatsminer M60S	refurbished, under 6 months of use	$18 to $22/TH
Antminer S21 non-Pro	refurbished, under 12 months of use	$18 to $22/TH
Antminer S21 Pro	refurbished, rarely offered	$22 to $25/TH

Above those levels, the discount to new no longer compensates for the absence of a warranty. A new S21 Pro trades around $25.6/TH: paying $25/TH for a used machine with no support makes no sense.

The 30-minute pre-payment checklist

Tick it on site. If any box cannot be validated, do not pay.

Visual inspection, 5 minutes

• Serial number legible, neither scratched nor covered
• No corrosion on connectors or hashboards
• Fans intact, blades without visible damage
• Sealing gaskets without leak or deposit, on a hydro model

Cold boot, 5 minutes

• Full boot through to pool connection
• Web interface reachable, on stock firmware
• All chips detected in the firmware dashboard

Wattmeter measurement, 10 minutes

• Wall draw inside the specification range, within ±5 %
• Startup peak below 1.3 times nominal consumption
• Consumption stable after 10 minutes of running

Hashrate verification, 10 minutes

• Effective hashrate at or above 95 % of nominal
• All hashboards within 5 °C of each other
• Hash error counter at zero over 5 minutes of monitoring

A 24-hour burn-in stays preferable, but this checklist catches the large majority of defects in half an hour, which makes it workable for a private transaction.

Field reports, 2024 to 2026

Two refurbished S19 Pro bought through classifieds, $4,200 each. One of the two had a dead hashboard, and the seller refused the return. A straight loss of about $1,700 on the investment, more than the saving made across both machines.

Eight S19j Pro+ bought at asicminer.fr, $17,000 total, 60-day warranty. All eight were still running without incident after eight months. The 10 % premium over the open market was repaid by the absence of RMAs.

Twelve M30S++ imported through ECOS.am, $9,200 total CIF. Three machines arrived with weak hashboards, and a partial refund of 35 % was obtained from the seller. The operation stays profitable, but the resolution delay compounds customs and shipping risk.

When to walk away

Four situations where price stops mattering:

• the seller insists on a cash payment with no invoice;
• the machine is visible only in photos, with no visit or test possible;
• the serial number is described as unverifiable or from an old lot;
• an aggressively tuned third-party firmware is installed and the seller refuses to return to manufacturer firmware.

Back to New vs Refurbished ASIC, Buying an ASIC Miner, and the Bitcoin ASIC guide.

Disclaimer: Bitcoin mining carries a risk of capital loss. Buying used adds a hardware risk no warranty covers, and the $/TH references above move with the market.