Aha ! Finally got my Mavic Air 2 to start up again. Had been so long since I flew. thought I was going to have it repaired. Was 2 years since last flew. Problem error was human. Reason was when I pressed my battery to startup nothing happened - then realised I had forgotten to hold down the button on the battery longer till everything started up !!! So simple..... Time to go to the neighbors field again.. Yipee !!!