Damaged K3S

[K4JST]

Al & Rick & others,

First, thanks for the continued input on this troubleshooting project!

Looks like I will be taking the front panel off today (a skill I never expected to need).

For others who may be following this, perhaps you may dig into a similar project in the future.  If you are working on an Elecraft project, make sure you download the Assembly Manual before you take anything apart! Also, take photos with your camera at each step.  When you get to my age, you will need them.

There is another thread on this same project going on the Elecraft Groups.io site.  I won’t try and duplicate their suggestions here, but you may find them interesting.

73 de Gil K4JST

[WB3GBL]

KN3U hi Al:   Yeah I've since noticed that C102 would pertain only to the contrast settings on the display, but C102 did pop up a few times on my google searches.  As far as sources go, most of what I find are the "usual suspects" - elecraft. groups. ico, elecraft ftp, and of course here at hamcommunity. However I try to tailor my google searches in a pretty tight manner, specifying the exact description of what I need to know - in years of experience of searches for solutions for Netware and Microsoft Network problems (and lately Ten Tec vintage topics)  -  I've developed almost a "sixth sense" for what might be valuable and what results are just advertisement distractions and circular meaningless responses. So most of the time I get back the most popular sites as results  - but it's those obscure archives here and there that bring the good stuff.

Kind of disappointed that the d28 diode was not the great circuit saver that it was touted to be but have had thoughts that maybe it was not the first device to see the transient abnormality that ravished the K3s. It's not always the voltage to ground that gets ya', it's sometimes its the lower to high voltages that can also generate the same effect as a current looking to find a route to discharge - like the purpose of blocking diodes in solar panels. Hence a thought that the D28 might have been the last component to react to the culprit instead of the first. Oh well, so many routes to lead to "red herrings" and of course like you've said the computer microprocessor has its own mind made up to follow a course that my be corrupt...   

wb3gbl rick

[WB3GBL]

Mike, K8CN / Gil K4JST -  It looks like POWERHOLDON would need to go LOW in order to make /PWRON  go HIGH to shut down Q2 on the RF board resulting in complete power down. The POWERHOLDON is generated internal to U1 (somehow unexplained)  out of PIN74 from the microprocessor U1 on the front panel Unless there is another write up somewhere explaining how U1 on the front panel circuit handles this chore this may remain a stumbling block in trying to apply logic to this problem.  However, I see there is one power related input to the microprocessor U1 - VPWR_SW.  To me it appears that if VPWR_SW goes HIGH two times, the microprocessor U1 switches  POWERHOLDON to a reversed state = LOW and forcing a complete shut off.  Absent using a scope triggered on by the on/off button signal, I would at least try to jot down the states of:  PWRON, 12V_UNSW, POWERHOLDON and VPWR_SW while powering up and trying to shut down. I assume that the power button does turn the rig on initially.  If  POWERHOLDON  never changes state then either the microprocessor is not doing its job or the signal VPWR_SW state change is not occurring.  Finding these signals mentioned should be easy to find on the Elecraft schematic sheet below:

References - Schematic sheet Elecraft K3: Front Panel - Power and RTC

Document Number  2004070601 A0 B

6 7 Sunday, June 24, 2007

I'd look real close at the path of the VPWR_UN signal to see what's around it and how that may effect the other symptoms going on. 

 

It is kinda' difficult to get my logic working tonight because my printer is dead and I'm flipping back and forth from this page, to my notes and the Elecraft schematic. HI HI 

Let me know if you believe that any of my signals here are crossed (inverted)! 

 

Have a great evening  wb3gbl rick

[K4JST]

Rick WB3GBL, Al KN3U, Mike K8CN and others who responded to Damaged K3S,

 

First thanks to all who took time to respond.  At this point, I am at the end of my capabilities with this project.  The receiver is working, the computer is talking to the rig, but can not do a Factory reset.

Have decided to have it repaired and am Sending it to Alan Wilcox W3DVX  Wilcoxengineering.com.  Will have it repaired and complete realignment and configuration.  He promises to supply a full report of what he finds and I will post a summary here and on the Elecraft groups.io forum.

I learned a few lessons and discovered, there are a bunch of hams who know far more about this rig than I will ever know!  Discovered Hamcommunity and a fine addition to our hobby.  Will plan to come to the picnic next year (just could not do it last Sunday) and meet some of you in person.

73 de Gil K4JST

[K3MRI]

Just now, K4JST said:

Have decided to have it repaired and am Sending it to Alan Wilcox W3DVX  Wilcoxengineering.com.  Will have it repaired and complete realignment and configuration.  He promises to supply a full report of what he finds and I will post a summary here and on the Elecraft groups.io forum.

Hi Gil.

Thanks for the update. Also, let us know how the repair goes with Wilcox. It’s always good to know what kind of service + results one gets from providers, which makes me realize that we do not have an entry yet in our gear repair directory listing. I’ll add Alan and then you can review.

Did he give you an idea of price range and/or repair time?

Jim

[K3MRI]

Done. Posted Wilcox here: 

 

[K4JST]

On 8/22/2022 at 6:51 AM, K3MRI said:

Done. Posted Wilcox here: 

 

Thanks,

Have talked to Alan several times and I have no doubt he knows what to do with my rig.  My K3S should arrive there today and I do promise to post a summary of what he finds and my experience with this repair and alignment.

73 de Gil K4JST

[K4JST]

An interim report on the damaged K3S.  I sent the rig to Dr. Alan Wilcox.  He found multiple problems on several boards.  He will supply specifics when the rig is repaired and alignment and configuration and firmware up dates are completed.  At this point two boards are off to Elecraft to be swapped for working and certified refurbished boards.  At least one board (the power amp) had a number of changes after my serial number. Pricing on this was really quite reasonable and needed to be done even without the damage.  Everyone at Elecraft knows Alan,  His website www.wilcoxdengineering.com lists his services for Elecraft products including K1, KX2,KX3’ K3, K3S and K4 (he owns and uses them all) and has been doing repars on Elecraft equipment for years.

email. Alan@wilcoxengineering.com for more information

 

Final summary will be published here.  I want to thank everone who had input or followed this project.

 

73 de Gil K4JST