My ego 20 inch 56v LM2001 will start but dies after a few seconds. I have already fixed the issue with the slide bar switch. The battery is charged, light stays green the whole time. Blade spins freely - not starting on the lawn, no resistance. Could the "key" switch, or the switch at the base of the handle cause this? Or is there something else? Love the mower - worked great till now - even the slide bar issue was an easy fix - hoping this will be too, once I know what's causing it. Thanks.