Problem with Innosilicon A4+ LTC master

I’m having a problem with my A4+ LTC Master. After switching the power on the red fault light starts to burn and the fans start running at a high RPM. I am not able to find the A4+ in my network, neither on I also do think I’m not able to update the firmware since a TF card reader is missing. Do you have any idea what the problem could be?