Could be the hard drive, when they get fault they make various kinds of annoying repetitive sounds. If it is the hard drive, then the unit would need replaced. Any recordings you had on it wouldn't transfer over to the replacement unit. A member of the Forum Team here can do some remote diagnostics on it (up to three days to get a response from on of them), or if you prefer, call into 150 and report a TV fault, the choice is yours.
- - - - - - Any opinions expressed by myself are entirely my own and do not represent Virgin Media in any way.
Welcome to the Community, I'm sorry to learn about the thumping noise your hearing at the moment, it's certainly not something we'd expect.
I'd like to test your TiVo box, but I've not been able to locate your account using your forum information unfortunately. So I can take a closer look at this, could you respond to the private message I've sent with the requested information?
You can view the message by clicking the purple envelope on the top right of this page.
Sorry again for the inconvenience this is causing, we'll speak soon