Hi shaun,
Tried those a while ago but couldn't find a way to copy good firmware to a USB stick, as it seems not recognised, or I'm not pressing the right code to do it.
If I have the full USB firmware, the set won't start so I can't use it.
Note that reading the Eeprom tends to give maybe 2 mb but firmware as downloaded is at least 10 Mb often much more, so suspect the on board Nand Flash is involved, and is liable to be terminally corrupted.
Recall a chap on Quuq recently, having examined/replaced Vestel Nand Flash chips, as was the case. Best of luck - Chris.