The purchasers of second-hand mining machine should pay attention to the following problems, to avoid from fraud.

As the market changes, some miners will replace their old machines with new ones for the considerations of revenue, security and operating costs, hence the second-hand mining machines come in. Miners may choose to buy second-hand mining machines due to the consideration of cost performance or the inability to buy suitable new mining machines. However, the purchasers of second-hand mining machine should pay attention to the following problems, to avoid from fraud.

·To buy from a legal company

The channels of second-hand mining machines are very complicated. Miners should purchase second-hand mining machines from companies with a track record of long operating time and good reputation, negotiate with it the transaction and after-sales terms, and clarify the responsibilities and obligations of both parties so as to safeguard their rights and interests thereafter.

·After-services are available

When trading second-hand mining machines, the seller will generally make the promise of "Guarantee for hashrate and installing on the rack". "Guarantee for hashrate" is the promise of the second-hand mining machine, and "guarantee for installing on the rack" is the promise of the normal operation of the mining machine after installing on the rack.

It is an industrial rule for the sales of mining machines, that unless there is a very serious quality problem, no return is acceptable. Generally, when trading mining machines, buyers can't see the real objects, and the quality of second-hand mining machines is more difficult to grasp. Therefore, the promise of "Guarantee for hashrate and installing on the rack" is very important to buyers.

·Second-hand mining machine under warranty

Some second-hand mining machines are relatively new and still in warranty period (“under warranty” in short). The price of such used machines is also relatively high. Check the SN code of the machine to find the remaining warranty period, this method can verify the seller's statement on the machine.

In addition, attention should also be paid to the mining machines under warranty that, in such cases as disassembly, assembling, swiping unofficial firmware, etc., the rights and interests under warranty will disappear, and the official franchiser will charge high after-sales fees for the maintenance of such machines. This should also be paid attention when you buy the second-hand machines. Do not buy mining machine at guaranteed price if the rights and interests under warranty disappear.