how can i play x box and wii on my lodos tv ?

I have a fairly new up to date Lodos TV model no CTV20TX but I have no remote control. It has red,white and yellow cables in the back to plug the wii and x box cables in but no of them will play. I have checked all 99 channels and have tried to scan through and tune xbox and wii in but none will come up !!! They both work fine on my other TV's Do I need to purchase a remote control so that I can simply press the AV button to make it work ? am very confused any help would be very gratefully received :-)a