Need help connecting set top box

[Hunain_2]

i have samsung led tv. there is no different inputs for av and component both are mixed up like yellow and green is one etc. my tv doing well for last 3 years but now suddenly it changes to component except av and my set top box only has 3 RCA cable. i thought as solution an adapter that convert 3 rca to hdmi. i bought that type of adapter online but it also doesn't work. Hdmi source doesn.t peak. so what is solution for that how can we say to motherboard that this is 3 RCA pins not 5 RCA component source. Please give me some direction how can i get my av source back.

 

[jsmithepa]

Perhaps the set-top box is broken?

 

[Hunain_2]

Perhaps the set-top box is broken?

No, its allright i checked that in CRD tv. it switches automatically to av sometimes and also revert back to component. majorly it detect component as input.
so i think there is not any hardware fault.