Replace those cracked and broken power leads. Shop around but, for your safety, choose replacements complying with standards. A quick look around for a replacement lead in Sydney shows you can pay AU$2 and die, or $6.95 or $13.95 and live.
When the plastic insulation on mains leads start to crack, replace them. Anybody could die touching the broken wire. you never know when your freid's young child will put a live lead in their mouth.
The $2 cables in the bargain bin often do not have safety compliance labels and are sold in shops where the shopkeeper would not know what to look for. Buy from a brand name shop so that you ge someone to sue if the lead fails in a fatal way.
I went looking for a replacement lead for a notebook power supply. The lead has the unusual cloverleaf design at the notebook end. Dick Smith has the right lead, product code W1350, for $13.95. Jaycar has the right lead, catalogue number PS4120, for $6.95. The Jaycar lead is advertised as complying to the SAA standard. I am sold.
The cloverleaf design is harder to find than the common lead with the IEC female plug at the appliance end. You can expect to find the IEC format lead for a lower price because it is in a lot of discount shops. Your choice might be $2 at one shop versus $3.50 at another. Check for the compliance label.