If Merish4 has not been updated to the release 2.3 or superior, you need to update it following the standard procedure as described on this page.

Once Merish 4 has been updated, download this file on your PC (about 130 MB).

Afterwards, copy the downloaded file into the main (root) folder of a USB-Pen, there should be only this file inside the folder, if possible.

Switch off Merish4, insert the USB-pen into the machine and restart it again.
If the whole procedure has been done correctly, shortly before entering the Song list a pop-up message will be displayed that requests to update the sounds. Press “Yes”, and the updating begins.

The process requests approximately 20 minutes.

In the end, switch off the device, then switch it on again after having removed the USB-Stick.