Update fail on one of my V6II unit, now it doesn't work
I bought a set of 4 V6II directly from the web store here November 2016, at first all 4 units seems to be working fine with my Pentax system, I've only used the setup for 1 shoot, earlier today I decided to update the firmware for them, first 2 units updated to V1.1.008 no issue at all, the 3rd unit started ok but when the progress bar reach the last little section, it stopped and a few seconds later come up with message "Error: Update failed", afterwards I unplugged the unit from PC, turn the unit on the screen flash V1.1.006 very briefly then a brief rolling message saying RF fail, then it just shut itself off and not responding at all. no matter what position the switch are on, and the screen is blackout.
With hesitation I upgraded the last unit but it went smoothly, now I am left with 3 units running firmware V1.1.008 and a paper weight....
Has anyone here encounter the same problem? Any suggestions?