Interference in small childs electronic cct - very strange!

[Always Learning]

My two year old got a book which plays a short tune when you open the back page.
This works all the time except when in one room of the house. It is the Living room and I tried turning off the tv, phone and even lights. Once I go to the doorway the tune plays as normal.

I'm going mad, can anyone shed any light on this??

 

[rwiggins]

Do you cut the power to the living room via the circuit breaker?

 

[Always Learning]

Nope, why, what are you thinking?

 

[rwiggins]

I'm thinking that electrical noise may be the culprit. Right now, I'm leaning towards a noisy switch or outlet, though it could still be an appliance. Have you had a chance to test it yet?

Added after 21 minutes:

I've also seen problems caused by flourescent lights (noisy ballasts, lamps loose, sockets, etc.) and incandescent lights (loose in socket). Switches and outlets which have aging and or loose connections and or faulty grounds can source noise. Appliances like televisions can source noise even when turned off because they usually have standby circuitry. Microwaves can source noise as can air conditioners and heaters. Get the picture? lol

Added after 5 minutes:

Oops, forgot to mention. Another source of noise can come from high frequency telephones. You might want to check that as well.

Other than all the above, without being there, I can only guess. But I am fairly confident that electrical noise interference is causing the behavior you describe. I'll check in later to see how your investigation is proceeding.