If you ring sky this is what they will tell you to do;
Switch off at the power socket. Leave the unit for about 3 minutes whilst all the components drain of residual power. Then switch on again and let the box power up and keep pressing the Sky button on the remote. If the remote command is not being acknowledged by the Small red flashing light on your box then your fault is with the remote. Now press the red standby button on the box instead to make the box come out of stand-by mode.
If this works then thank Bill Gates- It's called the Microsoft reboot.
If all the above fails then its hand in pocket time or better still if its an Amstrad box send it to Alan Suger's apprentice.
Seriously- good luck
Geoff in Wales, January 2011