The infotainment system on my Golf GTD suddenly stopped working after a brief stop. The screen logo appears as normal but then stays locked. None of the buttons either side work. The radio works but can only be controlled via the steering wheel control. Media does not work, even if a cd is inserted in the glove compartment. No access of course to menus, phone, or navigation. I've checked all the relevant fuses but as the screen is not completely blank this probably wasn't an issue. Have tried to reboot by holding on/off button down for the required time without success. Any ideas would be appreciated, although I suspect something hideously expensive has failed.