Thursday, July 26, 2012

Elecraft K3 P30 and P35 replacement


For a little over a year, I have had an intermittent problem with the K3. The problem occurred at boot-up (power-on) and at least two error messages were consistently displayed: IO TST2 ERRPL1 Once these errors appeared, the radio was unusable.

I contacted Elecraft Support and learned that these errors were most probably due to a connector failure. The culprits seemed to be the connectors between the front panel and the RF board. At Elecraft's suggestion, I purchased some DeOxit and treated the connectors. My experience was similar to other K3-owners on the Elecraft e-mail reflector – this fix only lasted a few months.

As I was getting paranoid about watching the display during boot, I decided to bite the bullet and see about a better fix.

Elecraft support advised that the best repair for this fault was to replace the original 28-pin P30 and 5-pin P35 tin-plated connectors with gold-plated ones and offered to send me the parts (at no charge) or to arrange repair. Though I am no longer a spring-chicken, I can still do through-hole soldering, so I decided to try the repair.
Important Note: I am NOT recommending you try this yourself. My advice is to return it to Elecraft. Personally, I weighed the K3 time lost, shipping + repair costs and probability of a botched job on my part and decided to give it a shot.

Before every step, I made sure that WB5BKL, the K3, tools and Earth were all at the same potential. I had a binocular magnifier, excellent illumination, an anti-static mat and a trusted soldering station available.

First I pulled the front panel assembly and then the bottom panel (I've gotten good at pulling the front panel assembly over the past year). I elected to snip off the pins as close to the plastic separator as possible. Then I carefully heated the solder joint and pulled the remainder of the pin. I later learned that it would might have been easier to remove the plastic separators – and then pull the easier-to-grasp pins.  Oh well.

Once all the pins were pulled, the most tedious task remained – most of the holes were still filled with solder. I used a fairly good solder-sucker I purchased at Frye's. This one was spring-loaded and my biggest problem was making sure the inlet was perfectly perpendicular to the RF board and heating the joint and pushing the solder-sucker trigger at the same time. Sort of like rubbing your stomach, patting your head and whistling “The Eyes of Texas” simultaneously.

All but about 5 cleared immediately. I spent quite a bit of time getting the final ones clear. I used a pin off the old connector to check the holes for clearance. I was afraid that if even one was tight, I might damage the new connector. I was also thinking that the board was through-hole plated, so the use of any force was probably a bad idea.

Finally, they were clear. I did several close inspections for solder bridges and then inserted the new connectors.

 

Soldering them was relatively easy. Another close inspection followed, revealing that I had missed one pin on the 5-pin connector! Yikes! Another inspection followed – and then one more. I checked the bottom of the board and touched up a couple of pins where it appeared that I had been skimpy with the solder.

One more inspection and then it was time for re-assembly.

I admit to being apprehensive about the first power-up, but everything seems to be working just fine.




Is it a permanent fix? I have no idea. Ask me in a year or so.

WB5BKL – Nick

2 comments:

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  2. It has been over one year and I have seen _no_ further problems. I hope that this is a permanent fix. I guess we will see in another year or so. - Nick

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