I updated the maps on my Go500 about a month ago, and all seemed to be OK. Just over 2 weeks ago, I wanted to use it to navigate from Newbury to Liverpool, but when I connected it to a power supply (the USB charger which I use for my mobile phone) it started up (drum sound), but when the progress bar at the bottom of the screen got to half way across, it stalled. After a further delay, the "wait" circle in the middle of the screen came up for about half a minute, then the icons indicating that it wanted to be connected to a computer, but wasn't. We didn't have time to do any more debugging, so I left it until after we returned from our holiday.
I tried connecting the device to a PC (Windows 10, with TomTom Mydrive connect), and after restarting, Mydrive reported that the device was restoring. The progress count reached 100%, then reverted to 0% and started restoring again. MyDrive reported that it was trying to connect to the TomTom, but never got there. The device is now well out of warranty - is there any hope of resuscitating it?