Casiotone MT-46 constant beep - fix needed

[Steffen]

Hello and thank you very much for including me in this forum!
I recently bought a fully working Casiotone MT-46.
However, a constant beep sounds immediately after switching on, which cannot be switched off or alleviated by pressing any button or switch.
Anyone have any tips on how I can solve the problem?
Many thanks for all information in advance.
Kind regards, Steffen

 

[The Y_man]

Not sure if this video will help....

The Y-man

 

[delaware dave]

No clue.....

Imagine calling your auto mechanic and saying "when I start my car I hear what sounds like a whistling sound coming from under the hood." Then you ask him "any clue on what it might be an how I can solve the noise problem?".

What do you think his answer would be to you?