Buzzing/interference sound on HDR


My HDR is playing up. I noticed that there was a buzz in the sound both on live broadcasts and playback of recordings. One of the kids knew how to fix it ... a gentle thump to the HDR over the Free view HD logo. It isn't a big issue (at present).

I was just wondering if this was a sign of impending doom of the box or just a loose connection in this area. I was thinking of changing the 500 GB drive to 2TB one so when opening it up is there anything I should be checking for.
Are you using Phono, SCART, HDMI, Optical or (God forbid) UHF?
Talk about vague...
If a thump fixed it, that points at a mechanical cause. The sound channel is not analogue anywhere in the signal chain within the Humax unless you are using SCART or phono outputs (you're not, are you??), so it can't pick up a buzz before it gets to the TV.

So we're looking at things that rotate - either the HDD or the fan. I plump for the fan (and the buzz is physically coming from the Humax, not the TV).
If the buzzing was in the sound channel, you would expect it to stop if the mute button was pressed on the HDR-FOX T2 remote control, or even if the TV's own remote control mute button was pressed.
Good idea, although it would be best to use the TV's mute (the Humax mute does not guarantee the buzz is not introduced later on in the signal chain within the Humax).

Another possible source of a physical buzz is anything electromagnetic, eg the power supply module, if a transformer or something is becoming loose or there is something loose within it.