Digistat SCR fault?

Hi I have a similar problem with the Drayton Digistat - hot water is ok - but no lights at all on the SCR reciever , & it seems quite warm ?? I have tried powering off the system and letting the the SCR go cold,on restarting the system both lights on the SCR glow faintly but the unit will not respond to demand for heating, is this a possible cap fault or somthing else - any advice would be great. Many thanks