Thread: gps62s startup issue, master reset won't work, any experts out there?

Hi - just back from a trip, before I left my and my mates 62s's both had the same issue - the screen would fade out on startup. Eventually that was resolved, I thought it was new batteries. I connected to basecamp and updated software. Trip went well other than that issue returning on last day. I can't connect to Basecamp, as the screen fades out the same whether on battery or usb. I've reluctantly tried master reset, but same deal, it gets to the point of asking if I want to delete all data, I have time to quickly select yes and enter, then it fades out. I've tried with and without sd card in, and everything else I've found on forums etc. No joy.

Any ideas?
Thanks in advance.....