Antwoord op "Why is my adapter switch itself off every so often"It will be the adapter over heating and shutting down. Let it cool off and then try again. It will likely do the same thing so I suggest you get a new one that is compatible. Did you try this with batteries?
Antwoord op "My battery charge only last 5 mins"If you can provide more information that would be helpful. I am unsure of what type of battery you have in this toy and if you can get to it.
Antwoord op "Why is my adapter switch itself off every so often"I have this keyboard for around 20 years and no have problems with the adapter so thinking yours must be faulty and likely overheating and shuts down to prevent damage. Try and find a new adapter and you will be okay from then on.