Hi Shaun,
Here's a thought - from Quuq old threads -
Wharfedale LCD3210AF LCD
Reverts to standby after 5 minutes and 8 seconds, caused by signal from IDTV PCB shutting down on connector PL500, even when the set was receiving an analogue transmission. Source of the shut down signal was coming from IC100 (STI5518BQC) which is a single chip set top box decoder. Inspecting the PCB indicated that pins 157 to 208 were not soldered from new, and a reflow did the job.
(Indicated in red on LCD2010AF picture)
Might be useful - Chris.