I did all this. I installed navcore in recovery mode, with MDC, with TomTom Business Solutions, variants 18, 20, 21 with and without patch. The problem with the sound does not disappear, but when the patch is installed, the problem with the start image also appears. The first time I installed the patch with navcore 18 in the device and everything worked correctly, then I updated navcore to 21, I reinstalled the patch and then the problems started. I installed the map of Europe in the device with MDC, also without result. It is strange that the device recovers if it is connected with MDC or TTActivator and stays that way until it is restarted.