Thanks for your post. Yes the fault is present on all channels and is
not related to reception or interference as I have tested the TV at
another location and the problem persisted. The fault is not present
using any external input (i.e. AV1, AV2, AV3 etc). Unfortunatley it is
not under warentee so I am left to fix the problem myself or pay to get
it fixed. As the fault is not present when using DVR on timer record I
assume it must be related to just one of the tuners (when timer record
is recording the fault can be heard when you view TV on the same or a
different channel during recording - I guess because the timer record
is using the second tuner at that time; as i explained earlier the
recording made during this scenario is fault free)? As any external
input and timer recorded DVR programs are unaffected I think it is fair
to exclude the amplifier circuit as a source for the problem, this is
also supported by the observation that the fault can be heard on
headphones.

Any ideas?
Cheers,
James