[Elecraft] MCU load failure; K3 not responding error message

[Don Putnick]

My factory-built K3 came with firmware version MCU 4.36 / DSP 2.73, 4-20-2011. I'm using the latest Mac version of the K3 Utility, MAC OS X Version 1.4.1.8 March 11, 2011. I've been able to save configurations, configure filters, and restore configurations with no problems.

I just tried to update my firmware for the first time to the latest production version MCU 4.39 / DSP 2.73, July 6, 2011. The MCU firmware failed to load, so I tried to force a download per the manual. At that point I got the "K3 is not responding" error message. I did a factory reset, and was able to reload my latest configuration. I repeated the firmware update, with the same errors. I've also tried reinstalling the K3 Utility and downloading the firmware again. No ceegar.

I'd appreciate any suggestions. Thanks much.

Don Putnick, NA6Z
K3# 5495