Two hours after starting the upgrade it hadn't moved, so I took a deep breath turned it off and tried putting the new firmware on the original Micro SD. I put it in and tried uploading it and it worked, like you said - in less than 5 seconds. When I turn the meter on the backlight flashes briefly but it's done that since I upgraded to 1.57. I'll test the meter out later and hope like hell that I haven't shagged it. I was just trying to use a faster Micro SD. Oh well, we live and learn, and make dicks of ourselves.