Can't re patch tv with set top box to watch tv

Question

Have a Sonawa (Chinese brand) 51 cm flat screen TV that has been used , along with set top box and VCR , to play kids play station. Now they've left it a mess and I can't remember how to patch it back the way it used to be so I can watch tv via the set top box. I managed to get the dvd playing on the tv monitor last night but that's all. Can't find the tv manual either so can't remember how it all links up.