Fixing a krubow RF Remote receiver

The USB cable of Les’ RF receiver broke one of its wires to the PCB inside, and resoldering it was difficult/beyond his skill.  He bought a new one (his 3rd!) and brought me the carcass.

The cable had pulled out so far the shield showed, and it was sort of held in with electrical tape.  The stub of the broken white wire on the PCB was very inaccessible, as it was embedded in what appeared to be epoxy.  Huh?  I broke the exoxy out, cleaned the holes in the PCB and cut off and re-prepped the cable end.

To my amazement, I couldn’t get the shield to accept solder at all.  As I tried to re-implement the clever mechanical approach of splitting the shield in two before soldering the other 4 wires, I realized why it had originally been epoxied:  Without being able to solder the shield, it was almost impossible to keep it in place.  I epoxied it, about as Keith had done originally (though I didn’t embed any of the other wires).  I’m guessing he soldered the other wires first, then put the shield thru the holes and epoxied it.

To provide a strain relief (so maybe I wouldn’t have to repair it again) I planned to embed the cable in Sugru.  And to help keep the Sugru in place, some .030″ baling wire rebar was installed.  (Its inside ends were epoxied in place.)

The rebar provided the additional benefit of a nice clamping place for the second bit of strain relief: casting the stub of the cable inside in epoxy.  (No, the case was not expoxied shut.)

Here’s the finished strain relief.  It looks and feels nice, and with the rebar hidden inside, I expect it will last quite a while.  Oh, yeah – the electronics work again, too.

Update ~10/21/17: Well, it was Les’ fault.  We had a C2 session in Skokie, and for the second time, I didn’t have all the parts for the remote control button.  I even knew it – but couldn’t find my receiver.

I’d forgotten that I’d used the leftover Sugru to make a strain relief (no rebar) for my receiver, and had put them both on top of the stereo receiver in the family room as a warm place for them to cure a little faster.  I picked up Les’ receiver and delivered it the next day, but completely forgot about mine.  Slowly – over a couple of hours’ driving to and from Skokie – I thought I might have done something like this.  And sure enough, there it still was!

This entry was posted in Miscellaneous and tagged , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *