No sound when playing Videos???

[MURFER]

I have just got a new philips VCR & have It conected up to the tv with a known working scart lead.

I get a picture fine but no sound from It??

If I wiggle around the scart lead I get some sound but mostly Interference.

Any ideas as I think that the scart conection on the VCR is duff.

Thanks

Murfer