[Elecraft] K3 - stuck at MCU LD we upgrading software

[N2TK, Tony]

Hi Jimmy,
Tnx for the info. I have a 35A switcher that loafs along. As I never have both K3's transmitting at the same time I am not taxing the supply. 
W3FPR got me on the correct track.

In your case, di d you check the voltage on the K3? Maybe you had a problem with a connection in the power supply? Down in the Caribbean periodically we have to take apart the Astron linear power supplies and clean the contact surface on the two bolts feeding the 12V output. They develop a little bit of resistance that drops the voltage under a load.  

73,
N2TK, Tony

-----Original Message-----
From: James Walker [mailto:jimmy.walker at outlook.com] 
Sent: Saturday, January 28, 2017 12:58 PM
To: N2TK, Tony <tony.kaz at verizon.net>
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3 - stuck at MCU LD we upgrading software

Tony,

I used to have this problem all the time. It was maddening. I never knew if the rig was going to turn on. It was always necessary to restart my computer to get my K3/100 to talk to the app that resets the firmware. I had several suggestions to fix the problem. The one that proved most helpful was to get a different power supply. I was using a big Astron supply feeding into a Johnson power strip. Several devices ran off the power supply. It should have been able to supply plenty of power for everything because the other devices were low wattage users like a keyer. Anyway, I had a smaller Anstron device that was once used with a 2-Meter radio. It was fully capable of 100 watts. I hooked it up and the rig as a dedicated supply and it has worked perfectly ever since. You may have a different problem than me but that’s my story.

Jimmy Walker
WA4ILO
Macon, GA

> On Jan 28, 2017, at 12:27 PM, N2TK, Tony <tony.kaz at verizon.net> wrote:
> 
> I believe this was addressed a while back but so far have not found it.
> 
> 
> 
> Upgraded firmware from 5.54 to 5.56. The one K3 did it fine. The 
> second K3 is hung up with the TX light flashing and the screen says "MCU LD".
> 
> And the USB port is no longer detected. 
> 
> 
> 
> I sure hope I don't have to do a complete reset that will cause a loss 
> of my settings.
> 
> 
> 
> Tnx for any advice
> 
> N2TK, Tony
> 
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