Sure. There's a K3 Utility Help topic on this in the most recent K3 Utility version. See K3 Help, Troubleshooting, MCU Load Failure.
Here's what the Help Text says (it's formatted better and there is a picture in the Help Text) MCU Boot Loader Troubleshooting When MCU firmware load is interrupted, or the power-on firmware checksum test fails, the K3 enters its permanent bootstrap loader. You can also force the K3 to enter its permanent bootstrap loader by turning the K3 on with a 10-second press of the power on switch. The MCU boot loader displays "MCU LD" on the K3 front panel LCD. LCD backlighting is normally off in this condition, so the screen appears dark in dim light. In order to load K3 firmware in this state, follow these steps in sequence. Turn off your K3 by switching off its power supply or removing the 12V power connector from the back panel. The K3's MCU can continue to run at very low voltage, and it's important that it start from a power-on reset. For this reason, it may be necessary to wait 30 seconds or so after removing power before power is turned on again. If you have a P3 panadaptor, remove its power plug so that the P3 does not power on, even for a moment, when you subsequently apply K3 power. Current P3 firmware sends commands during P3 initialization that disturb the K3 MCU boot loader. A future P3 firmware version will remove this constraint, but for now, unplug the P3 power if you find yourself in this situation. If the K3 Utility is running, select the Port tab, and then close the K3 Utility, using the File Exit menu item or select the red X at the top right of the main window. When the K3 Utility is started the next time, the Port tab provides the clearest indication of a successful connection. If you are using a sharing program or device between the host personal computer and your K3's RS-232 port (e.g. N8LP's LP-Bridge or microHAM's Router), change the cabling so that the host PC is connected directly to the K3 without an intervening software or hardware "forwarder". These programs send K3 "programmer's reference" commands, and a K3 in its bootstrap loader isn't yet able to process those commands. Some of the commands might put the K3 bootstrap loader into an unresponsive state. Restart (reboot) the personal computer that will run the K3 Utility This isn't often necessary, but occasionally a serial port or USB device driver doesn't properly close when commanded to do so. Rebooting reinitializes the device and its driver. Restore K3 power and press the K3 power button. You should expect to see "MCU LD" in an otherwise dark LCD, and the red Tx light should be blinking. Start the K3 Utility and navigate to its Port tab. The K3 Utility should find the K3 at at 38,400 bps. If the Port tab is selected, you should see a K3 Status popup that looks something like this: (picture can't be pasted into a straight text message) If you don't see this status dialog, try pressing Test Communications. If you don't see this dialog, the K3 Utility is not receiving responses to K3 commands, and it cannot load firmware without responses. Information in USB to Serial Adapter Troubleshooting may help to resolve this issue. The problem might be serial port cabling, an incorrect COM port choice, a problem with the Personal Computer, or the K3's internal KIO3 Interface. Once you see this dialog, press the "OK" button on the K3 Status dialog to continue. If the View Menu Trace menu item is checked, firmware load can take quite a long time. Uncheck Trace unless you require this diagnostic information. Select the Firmware tab, and click Send All New Firmware to K3. The K3 Utility should send MCU firmware to your K3, followed by any other "new" firmware required. 73 de Dick, K6KR -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of mark crossland Sent: Sunday, December 12, 2010 1:23 AM To: elecraft@mailman.qth.net Subject: [Elecraft] K3 firmware load Good Morning, My K3 will not come out of the mcu ld state and will not load the latest firmware. I have removed the power ,loaded the latest utility, and tried several times to load firmware,but to no avail. I reconnected the power and it is still locked in mcu ld. Any suggestions ? Thanks Mark ---W1VJ K3 427 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
