Hi @vickisworld ,
Here is a link to the ifixit [guide|6704] repair.
It shows how to open the toy so that access can be gained to the electronics.
Once it has been opened you can check the wiring using a DMM (Digital Voltmeter and also an Ohmmeter) to try an isolate where the problem is. Unfortunately I cannot find a wiring diagram for the toy which would greatly simplify this process.