How can I fix my Fisher & Parkel washing machine - model 608 6.5 kg?

The hot water works fine, however, when I connect the cold water, the washing machine makes a strange hissing noise and the cold water flow is very weak.

There isn't any problems with the cold/hot water taps in the laundry.

The machine is in very good condition, although I haven't used it for 2 years. It has always worked previously very well. What is wrong with it?

Please help me if you can.
I appreciate any assistance and advice.

Thanking you kindly.

Bruce