Anyone got a copy of robin 1610 manual. Looking for the display page. Think I've been conned. Bought from ebay Does all tests except insulation resistance. Shows a short as 0 ohms. But otherwise shows a line or a 1 on left of screen and a small square when I do insulation test. no idea what it means.Anyone seen this before. It is out of calibration but don't want to pay £76 if the thing's fried. don't know if I could claim my money back.I've had it a few weeks.But hadn't got round to using it.Any help or ideas would be brill.