Solved, but only wake up the fan and rollback to 15.2(2)E7

I face the same problem when upgrade to 15.2.6E2 and the fan not work.1. Press mode button to enter recovery mode2. Use usb to copy the 15.2.4E6 and info to flash drive3. Use set command to view the boot4. Boot= flash:/xxx15.2.4E6.bin5.Run boot to lo...

1. Press mode button to enter recovery mode2. Use usb to copy the 15.2.4E6 and info to flash drive3. Use set command to view the boot4. Boot= flash:/xxx15.2.4E6.bin5.Run boot to load the image6. Wait -> the fan turn on again7. Check config and wri