Hi @vishav, sorry to hear about your issues however if you have already raised a ticket with Tobii Support, they should be able to walk you through the stages to identify if there is indeed a physical problem with the eye tracker or not.
In any event, I would encourage you to try a number of tests such as: different USB port, updating USB Drivers & BIOS of the PC, trying a different *computer* if possible. Assuming the ET functions elsewhere, it may be useful to ensure your Windows 10 is fully updated as certain updates in the past have been troublesome for certain users.
Please let us know how you get on. Thanks.