[Elecraft] [K2] On initial Power-up, '"INFO 201" Remains

[dkredit10 at yahoo.com]

Now that the busyness of the Thanksgiving holiday is over, I was able to get back to the K2.

First of all, thank you all for your help and suggestions.

I first, for both the Front Panel and the Control Board, verified that all the proper components were installed and in their proper orientation.  No problems found here.

I then went and reflowed all of the solder joints (well, all of those I could actually access).

After reassembling the radio, I turned it on and got past the INFO 201.  Good!  Reflowing the solder must have fixed something somewhere.

Now I have the INFO 080 message.

Referring to Appendix E of the K2 manual, I quickly found the problem to be a bad solder connection on U1’s (RF board) 4 MHz resonator (RF-Z5)..  Easily fixed that and checked all other solder connections of the RF board.

Applied power. Ah, the wonderful sound of clicking relays!

Looked at the display, and saw...gibberish.

Decided to reset the radio again (4+5+6 then power-on).

Got the INFO 201, followed quickly by ELECrAFt, followed then by 7100.00c.

All tests and functions as outlined in Alignment and Test, Part 1, worked as expected.  Happy to see that!

Something still bugs me though. After reflowing the solder connections, I re-measured the resistance checks (per pg. 29 of the User Manual).  I only list below the measurements in question:

Test Point	Signal Name 	Res. (to GND)	Actual Measurement
U1 pin 1 	IDAT 		25 - 35 k	8.84 k
U1 pin 2 	ICLK 		25 - 35 k	8.93 k
U1 pin 3 	/SYNC 		40 - 60 k	28 k
U1 pin 5 	5A 		15 - 40 k	4.1 k
U1 pin 12 	2V 		9 - 11 k		6 k
J1 pin 15 	VPOTS 		10 - 60 k	4.3 k
J1 pin 16 	ICLK 		25 - 35 k	8.9 k
J1 pin 17 	IDAT 		25 - 35 k	8.7 k
J1 pin 18 	5A		15 - 40 k	4.1 k

I realize that the primary purpose of the resistance measurements here are to check for opens and shorts, but given that the three boards appear to work as expected, I can't help but wonder if these measurements are OK as is, or is there something else amiss.  I did check these with two different DMMs and the results were consistent.

73,
Dan, K7DJK


From: Don Wilhelm
Sent: Thursday, November 16, 2017 5:07 AM
To: dkredit10 at yahoo.com; elecraft at mailman.qth.net
Subject: Re: [Elecraft] [K2] On initial Power-up, '"INFO 201" Remains

Dan,

The MCU is apparently not completing the initialization process.  The 
INFO 201 should be shown only once (and not in normal operation).  It 
will be shown once after a Master Reset.  It should finish in about 30 
to 40 seconds.

The first thing to check is the soldering on the Control Board.
Reflow the solder adding a bit more (to add a bit of flux).  Use a hot 
iron (750 degF) and dwell on each connection until you see the solder 
flow out onto the solder pad and the component lead - that should take 
about 3 seconds, but if it takes up to 5, no problem.

73,
Don W3FPR

On 11/15/2017 8:55 PM, Dan, K7DJK via Elecraft wrote:
> Need some help here.
> 
> Been working on my K2 S/N 7770 and got to the point where power is first applied.
> 
> Upon pressing the Power button, got the INFO 201 message, but it just remained on the display.  It never went away and I never saw the ‘7100..00c’.
> 
> Turned power off and then cycled it back on.  Now, the display is simply blank.  Nothing.
> 
> I reset the K2 (pressing 4-5-6 then powering up), and the INFO 201 came up again with the same symptoms.
> 
> Would appreciate any thoughts on what might be happening.