A few things to try and/or make sure of....
If you have the modem plugged into a power strip or surge protector, please try plugging it directly in to an outlet to see if it makes any difference. Also, please make sure that the power plug going into the back of the modem is not loose. Please be careful with this plug, as it is delicate. In addition, please make sure that the coax connector at the back of the modem is finger tight. It doesn't need to be any tighter than this, but it shouldn't be loose.
With this said, the reps will be the ones to help you with this issue. They're on M-F from approximately 8AM to 5PM EST, though it may take them a day or two to reply.
In the meantime, please make sure to leave your modem plugged in so that the reps can not only run remote diagnostics on your HughesNet equipment, but also see any logged events, like faults, which can help them to pinpoint the problem.
I'm glad you found the community, thank you for posting. I pulled up your account and reviewed your case notes. I see that you've already called in about this after posting, and that we've already sent you a replacement modem. Let us know it works out for you.