Hi @michaelgurran,
is the TV's red standby power light on?
If so try a power reset and check if that resolves the problem.
Disconnect the power to the TV and then ''press and hold the TV's power ON button'' (not the remote's) for a full 30 seconds and then release it.
Reconnect the power to the TV and check if it can be turned on using the ''TV controls'' and then if it can, try using the remote control unit.