[Elecraft] Info 080 message started with RF Alignment and Test, Part II

[Vic K2VCO]

Try resoldering the connections to the MCU socket. Look at connections with a magnifier, 
and heat and add a bit of solder to any that look grainy or otherwise not good.

The fact that it worked partially and then stopped working suggests a flaky solder joint 
rather than a wiring mistake!

On 10/24/2012 9:10 PM, AC8HU wrote:
> Hi all -
>
> Started build of my K2 a few weeks back and have been slowly progressing.  I
> must say I'm not an overly experienced builder - I've built a number of
> smaller kits, the largest being an MFJ shortwave regen receiver and one of
> the "Ice Tube" clocks you can find online - but all of my builds thus far
> have ended with success.  Through Part 1 of the RF board tests, all was
> well.  Upon reaching the part 2 tests, things appeared to be fine as well (4
> MHz Oscillator Calibration checked out ok, and PLL Reference Oscillator
> Range Test was fine as well).  However when I proceded to the VCO Test, the
> problems started - with the first appearance of the Info 080 message.  I've
> had no luck in fixing the problem since.  Here's what I've found/checked:
>
> 1.)  X2 on the control board is the proper crystal - I was able to hear it
> on another receiver and zero-beat it by adjusting C22
> 2.)  Resistance between pin 28, U1 (RF board) and pin 40, U6 (control board)
> is 197 to 198 ohms - well below the 900 to 1000 it should be
> 3.)  Voltage on pin 28 of U1 (RF) is 0.14 V (close to 0, certainly nowhere
> near the 5-6 V range) - this apparently indicates that U1 is not programmed
> AND that the Aux Bus is open, although I've had no luck figuring out where
> the problem is with the Aux Bus
> 4.)  Checked voltage on pin 32 of the MCU (U6, control board) and found it
> to be exactly 5 V - checks haven't indicated any problems with the MCU I can
> find
> 5.)  I currently have no relay sound at startup.  I did previously (even
> with the first few startups of the Part 2 tests) however sometime after
> these problems started, the relay activity stopped.
> 6.)  Checking pins 1 and 20 of U1 on the RF board both give me 6 V
> 7.)  Measuring pin 28 of U1 to ground with power off gives me a high
> resistance value
>
> I attempted a "456" reset as I've seen mentioned elsewhere - this seemed to
> do no good as following the 10 seconds of Info 201 message, instead of the
> "Elecraft" message, I got the Info 080 message again.  Pressing any button
> to continue past that results in a display of 00000.00 and what looks like
> part of the number 2, NOT the c to indicate CW mode.  I assume this is a
> result of U1 not properly communicating with U6 at this point.
>
> Any suggestions?  At this point I'm fairly certain I have a fried (or
> "unprogrammed") U1, but I suspect I've got some other problem as well.  (I
> have been using an anti-static mat and wrist strap while building, however
> my soldering iron itself isn't grounded and perhaps should be.)  I'm quite
> the novice in terms of electronics so I can't really interpret the numbers
> I'm seeing other than to compare them to the baselines and see where things
> aren't correct.  Not totally discouraged at this point, but definitely
> distressed...
>
> Thanks in advance for your help!
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/Info-080-message-started-with-RF-Alignment-and-Test-Part-II-tp7564545.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/