Simple Demo Test of HD210, Won't startup...

I'm trying to test an HD210, but can't get the unit to start and display the basic Mountains demo. I had this unit operating previously, to test it after I purchased it. Initially I had the Err LED flashing intermittently, so I reformatted the Micro SD card, and reloaded the demo files. I'm using a microSD in an SD holder. Didn't seem to be a problem before. The Busy LED flashes intermittently. I've tried the VGA and HDMI outputs. Initially the HDMI output was correct. Any suggestions??