OK so call me dumb but I managed to totally brick 3 (new from Digikey) FRDM-KL26Z boards before I figured out that you can't... or can't on a Windows 10 machine. Apparently all it takes is to connect the board to computer via Mini USB with the button held down. That's it "poof" it's bricked, the application is instantly wiped (shows ver 0) in PEMicro info page. All I wanted to do is what I read was recommended, that is to update boot loader from 1.09 in this case to 1.11, and then update the application (boot loader and app available from PEMicro site). I mean I've done it before but must not have been on Win 10.
So I'm simply asking what I can do to reinstall the firmware from the ground up. Don't even think about sending me to the video link where it shows Group Policy settings. THAT DON'T WORK! I now have access to a JLINK DEBUGGER and have installed the 10-pin SWD connector. I have an older KL25 and the JLINK can connect no problem but it can not connect to the KL26Z's where the boot loader got bricked (meaning when you power up holding the button down all you get is 7 or 8 quick LED flashes with a second or so in-between).
Right now I'm out $60 + shipping and not a happy camper. I just want to get one of these working for a project I'm supposed to work on. I don't even care about OpenSDA now as I will just use the JLINK assuming I can connect to the board in MCUXpresso which I can't now. It's really unbelievable to me that these are still being sold with no warning about how easy it is to render them useless. And then no way that I can find (at least) to fix. I would send them to NXP if they could fix but it's a big company and no idea how to do that. Nothing wrong with the board just the firmware on it. So if you know about this issue I'm talking about (someone must) and know how to fix (have a easy to follow procedure) please post it as I'd be very grateful for it... Thanks!