Power Cord

Most likely you are going to have to remove the battery, open the case then bend the small metal prongs that [are supposed to] grip the plug when inserted. Those prongs or spring tines apply tension but over time, they lose that.

Unfortunately, once metal loses its tension, you can bend it back but it will never be as strong as new - it has to be reforged. This means, it is a temporary fix. The connector will eventually have to be replaced. How long it will last is unpredictable.

Now I am assuming it is the tension and not the mounting mechanism that is supposed to hold the socket in place. If the mounting mechanism is broken causing the socket to be loose (which you should be able to see once opened), a nice blob of hot glue, or epoxy putty can put and hold everything back in place. Epoxy putty is the better, more permanent solution. But it takes 24 hours of leaving it alone for it to properly cure.

 

While not a permanent solution, try this.
https://en.m.wikipedia.org/wiki/Blu_Tack

In South Africa it is known as Prestik and has been used since 1970.

 

If only vice clamps were made of plastic! LOL