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Posts: 2,222 | Thanked: 12,651 times | Joined on Mar 2010 @ SOL 3
#33
Originally Posted by magick777 View Post
dr_frost_dk, I do appreciate your work, but please actually read the post before you flame. I'm not sure by any means that epoxy putty is "better" or "worse" than soldering, but, the decision to go down that route is informed by every thread on this forum, including yours, and I post here because I'd be interested in constructive discussion about it. Your considered opinion would be very welcome indeed.

First, we're not talking about a "glue" so much as a "filler"; this is key to the mechanical strength of the fix. By physically filling up the space around the sides of the USB port, we're not gluing it down to paint, we're building a foundation that should stop it flexing even the slightest bit relative to the board; "adhesion" is less of a concern to me than sheer "mechanical reinforcement". If the port cannot move at all, the adherence per se will never be tested. I actually ended up going over the top and back of the port as well, with the port itself protected by having a cable inserted.

Second, epoxy putty is more solid during application than either glue or molten solder, meaning less chance of getting it in the USB port - but it remains workable for a couple of minutes, so there's time to shape it, move it or remove it once it's in place.

Third, your "without any problems at all" is subjective. You had to file away part of the case to fit the board back in after soldering, which may not be a problem to you, but does mean that more tools and equipment are needed, and makes the process more complex. In the photo below, to the top right hand side of the port you'll see the indentation in the putty from refitting it into the case while still soft.



This means I don't have to mess about modding the case in any way, and also has the advantage that the lump of epoxy fits up hard against the case. There's far more putty under the sides and the back of the port than is obvious from this photo; I did the sides and back of the port first with the microSD board lifted off, trimmed it back level with the board and then put a lump over the top (with a cable in) before final shaping.

The end result
  • uses a semi-solid material which stays where you put it
  • uses a non-conductive material that can be applied liberally
  • surrounds the port completely, even filling the holes in the jacket, without rendering it inoperable
  • gives plenty of surface area in contact with the main board (contact with the microSD board is incidental)
  • avoids fouling the case, requires no case mods, and actually reinforces the repair against the case as well as the board
  • requires no soldering iron or Dremel-type tools for case modding and is cheaper to implement on a small scale

Obviously, this hasn't held up for a year yet, so I can't say it's better or worse than soldering the port down, but it is cheaper, more accessible, a less complex procedure (no case mod) and more comprehensive in reinforcing the port from all angles and in all directions. You can see the epoxy filling up the back of the port in this second photo - and the port works just fine for both charging and data after being completely encapsulated in epoxy. In order for that to pull out, it's going to have to break the case too.



My hope in documenting this is that for me at least, it addresses most of the concerns that I had after reading the many posts linked to from this thread about soldering or liquid glues, and it's a fix that's available to Joe Average in his bedroom without a workshop. Comments invited.
It took a while till I noticed the brilliance of the approach. AIUI it will fill up the empty space between receptacle and the "bay" in plastic case so the receptacle is fitting into the bay and held by case, not by board. This is brilliant and I pondered it quite some time ago but never it occurred to me to use this epoxy putty for that, I just thought "dang, the headset/AV-receptacle is held by plastic case and contacts to board via springs. It never will break. If only USB receptacle was like that!" - well, and that's the point to make this concept the ultimate fix for USB: not at all solder the USB receptacle rigidly to the PCB, nor glue it to anything (use silicon oil to separate the epoxy putty from both PCB and case)! Just use a "snap-in" fixation like it's used on AV-receptacle. As obviously we can't get spring loaded contact, I'd suggest to use short stranded wires for the 5 pins and one for the metal housing (shielding). Those wires will bend when you apply excessive force to the receptacle and thus deform the whole fixating contraption consisting of the case bay and the epoxy putty. They even may break without damaging the PCB irreversibly - e.g. if user manages to break the putty and pull out the whole receptacle. No big thing to fix it if that ever happens.

Asking for comments on this concept.

cheers
jOERG
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Last edited by joerg_rw; 2011-09-18 at 10:13.
 

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