When using tweezers and a portable desoldering gun to remove the heat sink on the Antminer S9 hash board, the temperature must be controlled at around 450 degrees Celsius. More step details:https://www.zeusbtc.com/articles/asic-miner-troubleshooting/1394-how-to-correctly-disassemble-and-assemble-the-chip-on-the-s9-hash-board#desoldering #heatsink #AntminerS9 #hashboard