Q: power cable

Richard,

Best solution is to take it (with the adapter) to your nearest Apple store or re-seller.   There is one in every major town here.   A Curry's or John Lewis store might also be OK but Apple should be your first choice.

The charging bricks are sealed and non-serviceable so yes, you will need to acquire a new one. Given the age, it is improbable the Mac is still under some form of warranty and thus qualify you for a freebie, so don't forget your wallet.

Also, don't cheapen out. The MagSafe connector is Apple-proprietary, and licensed only to very few others who can guarantee the level of service needed. Remember that if it goes, it will take the Mac with it and repairs or replacement be much costlier.

Hi Richard:

Here is a technote which shows all the different model power supplies from Apple. Find the right power adapter and cord for your Mac notebook - Apple Support

You can also get them from OWC. http://eshop.macsales.com/item/Apple/MC556LLA/

Kim