The Bitmain Antminer L7 fan’s specifications are introduced in this guide, along with a list of the fan’s potential issues.
Table of Contents
Ⅰ.Fan Specifications
use standard 12038 size 4-wire fan.
ⅰ）12038 means the fan size：120*120*38mm，as shown below
ⅱ）Fan speed and air output
The air output of the Antminer L7 is 280CFM, and the fan speed is 6000 rpm (individual rear fans are 4800 rpm, which can be replaced by 6000 rpm).
ⅲ）There are 4 fan power PINs
Sort in the same direction,the one marked with an arrow or a solid square is the first one ：
①cpu fan PWM：Intelligent temperature control
②cpu fan in：Speed measurement
③cpu fan PWR：Fan powered
④GND：Ground wire
Ⅱ.Troubleshooting
ⅰ）The control board fan number and the log number have the following correspondence.
J12, J13, J15, J14 correspond to fan_id=3, 2, 0, 1 in the log respectively.
ⅱ）The speed of the 4 fans are all 0
Typically, the issue is with the power supply. The 12V power supply is strange. Replace the power supply or plug in the 12V power cord to fix the issue.
ⅲ）The fan is missing, the total number of fans is less than 4, or the fan speed is 0 when viewed on the user panel.
①Replace it after checking the fan cable and fan extension cable for poor contact, as shown in the figure below.
②Replace the damaged fan right away.
ⅳ) Fan speed is too low
①As shown in the figure below, check for bad contacts on the fan cable and fan extension cable before reinserting it.
②The fan is damaged, replace it directly.
ⅴ) Physical damage or vibration
The fan blade has been broken, as can be seen in the picture up top. In this instance, it needs to be changed. The mining machine will vibrate due to damaged blades, doing long-term damage to the mining machine. There are also some fans with slight deformation, abnormal bearings, and deformation of the fan grille causing the fan blades to scratch the grille, etc., all of which have the same problem. In short, as soon as the miner’s fan begins to vibrate or make abnormal noises, it needs to be replaced.
ⅵ) Fan speed is too high
The fan speed of the miner has reached 30,600 rpm, and it is still operating, according to the working status interface. We use a 6000 rpm fan, and the speed cannot be increased to that level. The existence of a problem inside this fan has been established. It is advised to replace the miner immediately if such issues are discovered in order to ensure the stable operation of the device.
ⅶ）Broken fan cable
From the above picture, the fan cable has been damaged, which may cause a short circuit with the chassis or other cables. Typically, this kind of issue shows up as a low fan speed or a missing fan in the log, indicating that the fan is malfunctioning. It is advised to immediately replace the miner if such issues are discovered in order to ensure the stable operation of the device.
ⅷ）From the log or batch scanning tool, it can be found that the speed of one fan is much lower than that of the other fans.
When the aforementioned abnormality occurs, the miner won’t report an error, but this circumstance needs special attention because the fan is usually at fault. Damaged fans should be detected and replaced in time to avoid batch failures during shutdown. The mining machine’s performance will be hampered by insufficient fans.
