I've just tried connecting a VCR into the third SCART socket on my RP. There is no image. I've changed the input on the TV input to AV (composite) , still nothing. Plugging the VCR into AV1 works, and also into AV2- that works. Also tried the DVD into AV1, AV2 and AV3, all work except AV3. I have two SCART cables. Front S-Video works. Is the AV3 input dead?