bush lcd27tv006hd?

i have a bush lcd tv lcd27tv006hd and it went dead i looked on the net and was told i could get a power supply repair kit which i did, i fitted all components and now when i switch the tv on i get sound but no picture just a blue screen i can opperate everything with the remote and on the tv but just no picture,is this a common fault or have i done something wrong please anyone know what is the cause better still how to repair thanks to anyone who can help.