Be very careful when buying electronic equipment that was made in China.  I recently purchased an electronic keyboard from an eBay seller and the keyboard stopped working 1 month after I received it.  Neither the eBay seller nor the manufacturer would respond to my requests for assistance and of course there was no warranty on the keyboard.  The purchase was a complete waste of my money.  Take my advice, do not purchase electronic equipment that was made in China. 

We were able to identify the source of the problem.  The keyboard needed a 9 volt power supply, but a 12 volt power supply was provided.  After using the keyboard for a month, it seems that it overheated and stopped working. 

The keyboard was a JC-6188 made by Excellent Industry (Yiwu) Co., Ltd.  located in Yimu City, Zhejiang, China.  Beward of purchasing products made by this company.

JC-6188 keyboard