I'll hazard the guess that it's got a power supply that's failed,
probably a switcher. The buzzing noise(s) are the supply trying to get
going. The failure could be the power supply itself, they do that - just
crap out for no reason, well bad caps, failed component, etc, or the
supply is not starting because of a fault in the rest of the circuitry.
Finding tech docs for this could be problematic. It's probably from
China and having been rebadged makes it trickier. If you can find out
where it was originally purchased the store may have some info or an
"authorized" repair depot. Although a lot of them won't sell or give
info to the general public. Here in the states even companies that used
to be real good about making service literature available are dropping
that business.
A good tech may be able to ascertain the problem even without docs and
fix a power supply as long as it isn't a unidentifiable/unavailable
part. If the problem is part of the main circuitry - you may be hosed.
That kind of good tech won't come cheap, but won't be a rip off either.
Good luck.

tomh

wrote:

Oh, just discovered something...

When you press the power button, nothing happens for about 5 seconds
(bootup). After this the buzzing happens. HOWEVER, the buzzing is at
two pitches and changes at ~2second interval. At the same time, if I
look down the back, theres a red LED that alters in intensity in time
with the buzz.

I'm assuming then that a startup 'test' has failed, and that this is an
indicator of the problem. I'll open the back up this weekend and see if
theres anything marked around the LED that can indicate the exact
issue.

Hope that may help anyone in the know - I'll also update this thread
just incase it comes in handy for anyone else out there on the
interweb.

Ta!

Danabnormal